Once again here is my annotation of your game. I decided to change 'NAG annotation values' (! !? ?! ?? etc)
If I think you are learning something or just play good move I will put "!" or even "!!", if I think you OR your opponent is doing poor moves or pointless moves I will give "?!"
By this you can somehow judge, maybe, your improvement by counting how many ?! or ! you have comparing to previous games. I think this method kinda will make you want to play even better (little competition with yourself hehe)
[Event "?"]
[Site "?"]
[Date "2012.01.10"]
[Round "?"]
[White "NN"]
[Black "kartha"]
[Result "0-1"]
[WhiteElo "1480"]
[BlackElo "1495"]
[EventDate "2012.01.10"]
1. d4 d5
2. c3 Bf5
3. Bf4
{"Ok attack on c7" ---
This move intention is not to attack your c7 pawn. Its purpose are:
a) Development (if white moves e3 his dark square would be trapped and become 'bad'. So instead first move to f4 and gain some center control)
b) Putting more pressure on e5 point.}
3. ... e6
4. e3
{"Bishop diagonal is open and Bb5+ followed by Qa4 double attack is possible."
There is no danger. If Queen / Bishop gives you check just use c6!
If White will do Bb5+ you respond c6 and white wasted a tempo. (he have to move twice with that Bishop)
"Also pawn moves should only be played to help or hinder pieces."
Okey here is some rules from A. Nimzowitsch book "My System" --->
"A pawn move must not in itself be regarded as a developing move but merely as an aid to development."
"An important rule for the beginner is the following: if it were possible to develop the pieces without the aid of pawn moves the pawnless advance would be the correct one, for as suggested, the pawn is not a fighting unit in the sense that.... since obviously the attacking force of the pawns is small compared with that of the pieces."
"..the pawn moves are only admissible in the development stage when they either help to occupy the center, or stand in logical connection with its occupation; a pawn move which protects its own or attacks the enemy's center, for example."
}
4. ... a6?!
5. Bd3
{"I can exchange my bad bishop with whites good bishop."
Why do you think that your light squared Bishop is bad?
Usually Bishop is considered bad if it is blocked by your own pawns OR opponent pawns are placed in the same color (White's pawns is on dark squares mostly - that means your bishop is 'good' and it control h7-b1 diagonal which isn't bad either)
Do you understand now the difference?
Also why did you take his Bishop? With that move you helped him to develop. You don't want to do that.
Instead just retreat to g6 square. (and if he takes you then hxg6 and you have opened h-file (which is good). In that position it isn't bad that you have doubled pawns (because of opened file.)
I hope I didn't confuse too much!

}
5. ... Bxd3?!
6. Qxd3 Nf6
7. h3?!
{Pointless move. (also doesn't follow Nimzowitsch rules I annotated earlier

)}
7. ... c5!
{Good move. Attack opponent's center and if needed can open you c-file.}
8. b3?!
{"ok, if i push 8..c4" ---
Why would you even consider that?
"also with this move b3 White told that he would be castling short."
I'm confused! How did you came to this conclusion
(P.S. once again bad move if we follow Nimzowitsch)}
8. ... Nc6
{Good, develops piece.}
9. Nf3
{"g5, e5 are weak squares for black."
Yes, they are. Good point. I see you start understand this stuff. Nice!
"1) and c3 is weak for white.
2) How can I attack c3?
3) OK, with Ne5, Rc8 and opening c file."
Cool, you start using some strategy! Keep think like that! I'm proud of this.
"ok let me first open c file by exchanging."
Strategy was good, tactic not so good. Keep tension. Keep in mind sometimes threat is more dangerous than the execution!
I just would build tension via Rc8, Ne4 and then maybe cxd4. }
9. ... cxd4?!
10. exd4
{"White Bishop has good control on h1-b8 diagonal let me exchange that"
Good point. Yes his bishop is better than yours. So it is good plan to exchange your 'bad' Bishop to his 'good' Bishop.}
10. ... Bd6!
11. Bg5!
{"I got the control of that diagonal anyway."
Yes, you got that diagonal, but there is no threats or some problems which you create by controlling this diagonal.
Do you agree?
Instead what does this Bd6 it gains more control of center (e5 square; in other words you are one step closer to move your pawn to e5 if needed)
"Nf6 is under attack and Queen is pinned."
Yes this is good move from white too. Nasty pin!
I don't know if you see this, but h6 creates also weakness in your kingside. If I judge correctly you are going to castle kingside.
You may ask "How this creates weakness?
Answer: White can easely castle queenside (0-0-0) and then push g4-g5 and you king is already under attack.}
11. ... h6
12. Be3
{Yes Bishop loses (if we are technical about this) tempo, but white pressured you to make weakness to your kingside. Namely h6 move.
So with that in mind white benefits more than you.}
12. ... Rc8!
{Reasonable move.

}
13. O-O
{"Whites pieces are all eyeing towards Blacks King side. so instead of castling let me open c file and get more defense towards King side by moving Ne7."
I don't understand this. Why Ne7 instead of 0-0?
There is no near threats to your king (and you will have to castle anyway) why wouldn't you FIRST castle and then move Ne7 if needed?

}
13. ... Ne7
14. Nbd2 Nf5
15. Ne5 Qc7!
{Ahh you saw double attack. Good.}
16. Rac1 Bxe5
17. dxe5 Qxe5
18. Bd4!
{Strong move from white too. With this he will create doubled pawns on your kingside.
So there is some sort of compensation for lost pawn.}
18. ... Qd6
19. Bxf6 gxf6
20. Rfe1
{"OK discoverd attack on King..."
huh...
Please use chess terminology 'wisely'! (Know what does that word mean and understand it.)
According to Wikipedia:
"In chess, a discovered attack is an attack revealed when one piece moves out of the way of another."
Re1 IS NOT a 'discovered attack'
When you use words or terminology you think you understand but you don't really - you create confusion to others as well people will misinterpret you.
When use chess terminology at least check wikipedia:
http://en.wikipedia.org/wiki/Glossary_of_chess "moved Nh4 by killing Nxg2 and create open line threats."
I'm not sure I understand.
Did you mean g2 point is weak and you are trying to utilize it via teamwork Rg8, Rh4 both attacking g2? If so Rg8 move is more accurate.
Also if you choose to move you Rook to g8, did you consider your King's safety? Namely asking yourself:
"I will not be able to castle. Will my king be safe?"
Did you?}
20. ... Nh4?!
21. Nc4
{Kinda scary move, but it doesn't really threat anything. If you move Qd7 then there is fork Nb6. That is only threat I see. Just retreat Qd7.
This is tactics stuff.
Do you train your tactics daily? If yes how long?

}
21. ... Rxc4??
{Big blunder! You lose exchange unnecessary...}
22. bxc4
{If before you made 21...Nh4 you were better or at least equal. Now you are definetely much worse!
Your King isn't save. Your pawns is doubled. Your Knight is doing nothing in Nh4 square. White's pieces are more mobile. White's king is in safety (more safe than yours)
Overall this is very bad.
And to make from better to worse you had to make only 1-2 moves.

}
22. ... Kf8?
{OK, now you know intuitively that you are in trouble. You allowed pressure to make you play bad.
Do you agree?
Just play calmly and 2x stronger (concentrate more; because it is not lost). I have won quite many games when I just say "OK I'm worse than my opponents, SO I need to play 2 times better. And I do play better.
Ok about move. What is reason behind Kf8? It is pure mistake.
Why didnt you just 0-) and after that Ng6 (going to defense).
I guess you moves Kf8 because you now "maybe somehow I could use Rg8" The keyword is "somehow"...
You play aggresively when you have to change your style to defense.
Think about it!}
23. Re3?!
( 23.cxd5 exd5 24.Rcd1 Ng6 25.Qxd5 Qxd5 26.Rxd5 {And you are lost.} )
23. ... Nf5
{I guess white just didn't want to win.

}
24. Rf3 dxc4
25. Qxc4 Qa3
26. Qb4+!
{Good move. White want to exchange queens. You don't. White succeed.}
26. ... Qxb4
27. cxb4 Kg7
{"Protects f6 pawn and allows Rook into the Game."
Yes. But if you did castle earlier you wouldn't need to do Kg7 to activate your Rook. :p}
28. a4?!
{Better Rc7.}
28. ... Rd8
29. Rfc3?!
{Pointless move.}
29. ... Nd4!
{"If 30.Rd1 pinning Knight then 30...Ne2+ forks the Rook."
Good tactic!}
30. Kf1 Nc6
31. b5 axb5
32. axb5 Nb4
33. Rc7 b6
34. Rb7 Nd5!
{Excellent position for your Knight! It is pain in the ass.

Really, it wonderfully defends your pawn on b6.
Central knight can be VERY powerful. This is one of examples.
White with very poor endgame skill, has made this game drawish, I think.
On the side note, do you study endgame??}
35. Rd1?!
{"One possibility which I didnt saw in the game is Ne3+ equalizing the exchange"
Yes you are right.}
35. ... Rc8
( 35...Ne3+ 36.fxe3 Rxd1+ 37.Ke2 Rd6 {and draw.} )
36. Ra1 Rc2?
{Mistake.}
37. Raa7 Nc3
38. Rxf7+ Kg6
39. Rg7+ Kf5
40. g4+ Kf4
41. Ra1
{White just haven't got a single clue how to play endgame. Just poor big time!

I suggest to get endgame positons vs. this player. }
41. ... Kf3!
{What a powerful King!!!}
42. Rc7 Rxf2+
43. Kg1 Ne2+
44. Kh1 Ng3+
45. Kg1 Rg2#
{Beautiful!}
0-1
I challenge you and encourage to do more advanced analysis of your games. How? --->
If you do this your analysis will MUCH more enjoyable (yes, fun) and will benefit you even MORE! But it will take a bit longer.
Good luck, I hope this helped.