ok, i'll link to the game and then explain:

http://www.chess.com/echess/game.html?id=41551550

he's a superior player and we were very much even at this point. however, i couldn't see a way to finish him and i was worried that a mistake would result in a devistating loss. i chickened out and took the draw.

i need some tips ... i can't see how to ensure a win here. i thought about pushing pawns forward, but i feared losing my position.

please help me understand what i might have been able to do to get an win.

I think that 27. h5 should have worked

Dragec is right, 27.h5 would have left you up the piece.

If you're talking about the last position before accepting the draw; accepting the draw was probably a smart thing to do.

You could have waited for 1 or 2 follow up moves, because you have a mate threat and a series of moves which forces black's hand. Rd8 is pretty much a forced move for black here, and then that rook is confined to the back rank so long as your rook controls the e file; but what else are you going to do though? As soon as black plays g6 you would be closer to losing because you can't support the pawn on f7. With two rooks each left on the board, you're not going to find much of an opportunity to activate your king, and one of black's rooks is already targetting the weaknesses of your queenside pawns.

shazomei - thanks for the advice. you and dragec are right about the h5 pawn move ... but at that moment i was nervous about his rook.

i'm glad you said that i wasn't in a strong position to win the game. that's what i felt too. i knew he'd move his rook back and protect the king. my only option (i thought) was to march pawns and try to force him a little.

but i knew my position wasn't strong enough ... and being a weaker player, an error would have given him advantage enough to steal the game. 

I think you had a good move also with 23. Na4 threatening Nc5 forking the rooks.  His knight is still hanging so if he doesnt move his knight then you can take that if he protects against the fork.

I think Na4 isnt that good now because he has Bxa1 but the fork is still there for next move.

tactician, it seems that you missed that 23. Na4 instantly loses a rook: 23. ... Bxa1. Some skirmish occurs after that, but  white still loses some momentum and material.

good analysis dragec ... thanks!

This continuation also might have worked, it needs more analysis though(analysis shows importance of intermediate moves) :