my general thoughts on stealing
Steal as often as possible, the more the blinds are worth stealing the more you should steal.
Don't be afraid of differing stack depths, i see too many people worrying about postflop when they can make a profitable steal attempt and simply check/fold postflop. As long as your preflop move is profitable go for it.
Have a look at player tendancies and work out ways which best exploit those tendanices. Vs some players, raising is best(nits, aggressive players), vs others limping and betting any flop is best(passive limping type players who)
Also don't be afraid to find out what players are like. usually if you have no history you should be quite willing to find out how they react vs a raise attempt, If they keep folding to you, keep raising, don't worry about what they might do if you keep raising until it happens. What i mean is don't fold just because, "i've raised the last few orbits and i want to make my image tighter" You could be moved tables next hand and never see this guy again, just keep raising and taking his chips.
Keep in mind once you start to steal more, you will in general see more action and it will feel like you are being played back at more, this seems obvious, but not every steal attempt will work, so be prepared to go postflop when needed. obviously the deeper you are the less stealing is important and the more postflop play is important, and the less chips you have in relation to the blinds the more preflop stealing is important and postflop is less important.
Hope this babble helps