Hello fkrule,
Good to hear that you've set up an account with ND.
You can find out how much you've earned on our system by logging into your account. The first page is the portfolio statistics page and it shows how your domains have performed for you. If you click the Daily Stats button, you can see how the domains have done on a day to day basis.
On the RPM front, it is really hard to say for sure as there is no 'basic RPM'. This can range from 10 to hundreds of dollars depending on the quality of the traffic and the advertising sector it is from.
I hope this answers your questions. Feel free to contact me if there's anything else I can do.
Ed