The first thing you must be absolutely sure of is that the money you are removing from your personal life/family to spend in surfs or hyips (or any on-line program) is not any part of what is needed for the essentials of living. It must be extra money that, although painful to lose, would not cause serious financial damage to your long-term budget. There is a high possibility that you could lose all your on-line spends, especially if you are new to this crazy game.
One rule of thumb to remember is that the higher the profits on your spend, the higher the risk. However, any number of programs offering the same returns may still have very different risk levels, depending greatly on the honesty and capability of the admin running the program. Determining whether or not an admin is honest and capable is the hardest part in performing due diligence, but I believe it is the most important. If you know nothing about an admin, then you must assume he will disappear at any moment. If all you know is what is said by posters on forums, then you really know nothing about him because you can't rely on what posters say. If an admin has scammed in the past you must assume he has NOT reformed and will do so again. If the site looks unprofessional (missing terms, broken links, many misspellings), then you must assume the admin is incompetent and a higher risk.
Personally, I like to keep my risk level low so I rarely venture into a high-roi program (although I did too many times when I was a newbie), but some people enjoy the thrill of winning a high-risk gamble. It's a matter of personal choice, but do not spend blindly or you will soon be broke.