Originally posted by: Balt
There are some good tips in this thread, but there are also some very bad ones.
As others have said, you will need to do more than pushups to increase the size and strength of your chest.
Check
here for a list of exercises that will work your chest muscle(s). I personally recommend bench, incline bench, chest dips, and a lying or standing fly. The links will show you the proper form for these exercises, which is
crucial to seeing results as well as ensuring that you do not injure yourself.
The best piece of advice I can give you though is get the advice of a professional at your local gym. It may cost you a few bucks, but it will save you
a lot of time and wasted energy. They can set you up on a program to meet the goals that you want, but they will also help you to develop a
balanced program that includes more than just your chest. You aren't going to increase your bench by focusing only on your pecs. You need strong deltoids (shoulders) and triceps as well. The professionals will also ensure that you aren't going to tear up your body by using incorrect form.
As for the different sizes of your pecs, this is an unfortunate reality for some of us that don't have great symmetry. It is more or less a genetic barrier that can only be overcome with hard work, good form, and time. Stick with free weights so that you can't "cheat" by using one side of your body more than the other, as is often possible with weight machines.
Good luck!