How do they charge for senior pictures...?

Is it by the hour, the frame? I'm only a senior in high school. I started out doing just the senior pics for two of my friends because senior pics in our area cost around 500-600 dollars and VERY few people can afford that. I'm a decent photographer, I use a canon rebel xti and I have photoshop cs3, corel x2, picasa, kodak easyshare, and gimp and I'm pretty good with all of them. I know enough about cameras and the software to do a decent job but I don't have the equipment for an idoor studio [[no lamps or backgrounds...all I have is the pop-up flash that came with the camera, no other external ones.]] so after my other classmates so the work I did on my friends they also wanted me to do their's because they know it won't be costing them $500. I already have 15 other people who have scheduled with me and a couple the same age as me wanting their wedding portraits done by me...I just don't know how to charge them...I'm not printing them because I don't have a decent printer so...

our local printing store will do it and I'll just give them the cd...I want the cost to definately be cheap but I don't know how I would charge them...by the hour or frame or what??? [[all outside and some out of town...like 40 miles away...HELP!]]

i started doing senior portraits before i was a senior so i can relate. i usually charged 50 dollars an hour plus costs of prints [which you look like you figured out] and if you take time to photoshop you can add that in to the price. you'll make decent money and they'll be saving a ton. have fun!

if you have aim, message me 'omg buddha'