on the free surveys, go through them at the speed of a dyslexic 8-year-old, and look at (I don't mean you have to BUY!) at least one of the extra offers per page, then when you get to the 'thank you' page, get up, go potty, fix a cup of coffee, or wait at least 30 seconds so that they can deposit and/or/verify their cookies on your computer, and you'll have a lot better chance of getting credit. Make sure that your virus software is NOT running while you do these types of offers, as it will clean the cookies off as soon as they put them on, then they won't find them, and then, no credit. Wait a while before doing another freebie from the same advertiser (if it pays the same amount it's usually the same advertiser) because if you do too many too fast they will see it as fraud, and won't credit, don't do more than TWO offers from the same advertiser per day, same reason.
On the paid to completes, make sure you CAREFULLY read the FAQ's, write down the name of the offer, the date you did it, and all info you will need to cancel it before it goes to full charges in case you don't want to keep it. I keep a calendar next to my computer for all of this info, and at least two notepads at all times.
E-Bay, Google, and Yahoo Success are from the same advertiser, so you can really only do one of those per month, because your credit card will deny them the money, and then you won't get credit (at least they use the same billing company, and my credit card did, and when I called the company I did the offer with to ask why no credit, that's the explanation I got!)
Go to 'cccleaner' '.com' and download the free cookie cleaner, run it in between offers, and when you are done for the day. Go to 'spybot' '.com', and download the free software there called 'spybot search and destroy' and it will keep you from picking up the lovely little re-directing adbots that love to appear when you have done too many free 'paid-to-clicks', run it nightly.
I think that's most of what I wish I knew back when I started. Oh, yeah- read this forum, it will tell you which other sites are worth visiting, and some of the ones to stay away from. FC is one of the best, they always pay on time (most of the time early), and they have a pretty good crediting ratio, also a forum where we can help each other out.