California or New York? It might make a difference if you were looking for specific local stores.
In general, look at the big box sporting goods stores. They carry the lower end of the product lines for the major makers (Rollerblade, K2). They will be OK skates with the better features on skates that are generally out of your budget.
The advantage that you have right now is that the stores may be running sales on 2009 skates so that they can clear them out before getting their 2010 skates in. You can frequently get skates at 1/2 to 2/3 of the normal price. It just depends on what they have left in stock.
I picked up a decent pair of Rollerblade skates (4x90mm wheels, aluminum frame) for just about $100 last February for my girlfriend.
Larger wheels are better. Aluminum frames are better.
Get skates that feel snug all around your feet without crushing your toes.
Get a helmet and wrist guards (knee and elbow pads if you are less happy with the idea of scraping them WHEN you fall.
Falling WILL happen sometime.
The hands almost always get scraped up and hurt a lot while healing.
The head getting hit is less common but can leave you with headaches for months (know a person) or dead (knew a person) if you don't have a helmet.