I second the pushups vote. Do em for a few weeks and then start doing them with books under your hands (or whatevers stable) to build up the intensity. By doing them up on books, you get a deeper stretch with each rep and this helps with the chest development (and keeps you flexible) Along with pushups you should also do my #1 all time favorite exercie, the pull-up. Do pullups, do chinups, there are tons of variations as you get stronger.. Git yerself a bar at a sports place and hang it and do as many as you can a few times a day. The pull-up is truly a great exercise that works ALOT of muscle groups. If you can only do one, then thats a great place to start. Once you get to two, then three and on and on.. youll be hooked. Pull ups are hands facing away, chin ups are hands facing toward you. Chins are generally easier and may be the place to start to get your muscles used to the work.
So pushups for your chest, and triceps (mainly)
and pullups for your back, biceps and forearms (mainly)
you will no more be girly-man!!
have fun
~Steve
also you can try sprints while on the bike standing and in a tall gear, really working the bike side to side against your legs.. this is all upper body.