i posted this on gixxer.com a while back, and it semed to help some people out. these instructions are for a gixxer, but they are pretty much the same for other makes as well. if you have any questions, pm me.
ok, changing your sprockets and chain is pretty easy as long as you have the chain tool and a rear stand or someone else helping you out. the most popular combination would probably be -1 in front and +2 rear. afam makes very good sprockets and rk makes excellent chains, both of which you can get from
www.sprocketcenter.com
here are step by step instructions:
1. remove front sprocket cover
2. cover a breaker bar in cloth, and wedge it in between your rear wheel spoke and your swingarm (with the wheel moving in a forward direction).
3. remove front sprocket (i think its a 32mm socket).
4. support rear of bike on a rearstand, and remove the rear wheel.
5. remove sprocket from rear wheel (i think its a 17mm socket), and install new one.
6. using chain tool, remove old chain.
7. re-install rear wheel and your new front sprocket, but do not tighten yet.
8. thread chain around front sprocket and wrap around rear sprocket so that links meet on the back of the sprocket.
9. remove any excess links (if necessary).
10. using chain tool, rivet new chain together.
11. using the same cloth-covered breaker bar as before, wedge it in between your wheel spoke and swingarm (with the wheel moving backwards now)
12. tighten front sprocket.
13. align rear wheel.
14. ride bike.
that should be about it for the chain and sprocket swap.