First suggestion:
Take the class offered by the motorcycle safety foundation. The basic course is for people who want to learn to ride a bike (even if they don't put it in as many words).
http://www.msf-usa.org/ There is a lot more to riding a motorcycle than just hoping onto one and practicing by yourself. I **HIGHLY** recommend the course.
Second suggestion:
Don't buy a 250cc bike--you'll outgrow it in about 8 days. Instead, buy a 600cc bike that doesnt have a ton of HP. My suggestion would be a Yamaha FZR600. You can probably pick up a `96-98 FZR in good shape for about $2-3k.
(Edit)
Third suggestion:
Don't buy a new bike as a first bike. Buy used so when (not if) you drop it, it won't be that big of a deal. Also, cheap bike is okay but don't go too cheap when buying gear.