Your income will really depend on a lot of factors. As a new attendant you sorta have to pay your dues... It might take awhile before you reach your full potential. You have to develop a repeat clientelle; treat every client you see as best you can and be yourself... Regular clients who have you on their list of favourites and book appointments are what keeps a busy girl financially stable during slow times when other girls are sitting and waiting for a client to walk-in.
The max and min really varies. I have seen girls (even at the top spas), go home with nothing (it's rare but it does happen). I've seen girls go home with well-over a G on a good day.
Just so you know... it's not as scary as you probably think. Reading massageplanet.net is a good way to familiarize yourself with the protocol, where to work, what to do (and not do). I learned a lot from massageplanet.net (actually I found out about massage by stumbling accross massageplanet.net accidently lol). massageplanet.net is not the be-all-and-end-all. Not all clients are on here... But if you take things that are said with a grain of salt... it can be an awesome resource for you.
If and when you decide to give it a "go"... be nice to your co-workers and ask for help. Admittedly, not every girl will jump on the chance to help the competition lol... but there are always girls who will give you tips and some will even go out of their way to give you advice. No matter what you learn - from clients, from girls, or from massageplanet.net... only do what you are comfortable with - adjust the suggestions to suit your style, and be yourself.
MPAsquared will surely jump in here =) She's a pretty awesome chica, a superstar MPA, and she's a good one to go to for advice as well.
In my early-days, my co-workers weren't exactly welcomming to me... I know how it feels to be lost and I've always tried to help out girls who needed or wanted advice. If you have any questions, feel-free to ask
Good luck!