There are many sites you can earn cash back from when you shop online- Before I buy anything online I check with a few sites to see if they will earn me cash with the purchase I am about to make. It is pretty simple- click through the cash back site and find the store you are looking for. Click on the store and begin shopping. All the tracking is done by the cash back site-nothing for you to do. In a few days, you credit will post to your account. For most, you must reach a certain threshold before getting your check, others payout monthly.
Take a look at these- I have used them all, and they are all legit!
Ebates- earns you a $5 sign up bonus for new account. Has a $5.01 threshold, not including your sign up bonus, and pays out quarterly by check.
BigCrumbs- Pays you monthly to paypal on any amount you have earned!
ShopAtHome
MyPoints Earns you pionts you can turn into giftcards! I have cashed out several times- great program!
Kick It Back