How can you tell if a site is legit or not?

You need to check sites out before you go full speed ahead. If it sounds like MLM I would stand clear of it. I have been testing sites and products out for about 3 years and have found that MLM or Multi Level Marketing is not really something to get involved in. At least that was from my experiences. There are legitimate sites but you just have to check them out first. Most of the time unless you are buying a product, if you have to pay stay away.