first thing to do is get yourself a permit. it is a short test, pretty easy actually. just go to any dmv station and get the book to study from.
next thing is to get proper training. friends who have been riding for a while are great, but professional teaching will help you avoid all those little bad habits your friends don't even realize they have. it will also lower your insurance when you do get a bike of your own.
http://www.rider-ed.com/index.htm
another benefit of riders ed courses is that you don't have to take a road test at dmv. the completion of the course gives you a certificate that you can walk into dmv with and walk out with your new license.
later
tim