I have been making money online for several years and my earnings vary from week to week depending on how much writing I do. I also earn weekly Pay Per Click, such: Two Dollar PTC, Six Dollar Bux, Seven Dollar Bux, Ten Dollar PTC and Mistery PTC.
I have also made money by promoting affiliate products and referral programs such: SFI and Tripleclicks, Amazon, and ClickBank and also ClickSure, but again my income varied depending on how many people purchased a product and on the activities of people I referred into a program.
I think $10-$20 a week is good for a newbie. You have to think of making money online as a long term project. It could lead to full-time earnings in years to come, but does take time to build up egular income.