Motorcycle Questions

[JaBlue]

I want to get a motorcycle. I would buy it used and don't need it to go much faster than 80.

How much will it cost me and what other than the bike do I need? Is there any special maintenance involved? Do I need a special license or anything?

Any info would be nice, so if you know something about bikes that a guy like me who doesn't know anything about them doesn't know, please share.