(a) Before investing money into a program, you must investigate it thoroughly in addition to researching it.  You can check the program with 'Better Business Bureau' or 'BBB'. 

(b) Never invest in any company that you are not sure about. Always ask for references from people with whom they have worked with.  Call these people personally and discuss about the company. 

(c) Always avoid 'get rich quick' programs on the net. These programs are all scams.  There is no easy way to get rich quick. To get rich, you must work hard and it requires time. 

(d) You should never pay any money to get a list of work at home jobs or businesses.  This information is available freely on the net. 

(e) Try to avoid joining any company which requires you to pay an upfront fee towards registration, training etc. 

(f) Don't trust a company which has only a P.O. Box as its address.  

(g) Before joining a company, try to get specific information about it -- the time required to get paid, whether there is any refund policy, whether there is any restriction on payments etc.     

(h) When you invest money for any business opportunity, it is better to use your credit card instead of cash.  If the company is a scam and you need to get your money back, it is much easier to open a dispute with your credit card company than trying to get your money back in cash directly from the company.