Which Kind of Affiliate Program to Join ?

The ones that work for you! It depends what kind of audience you have (what kind of people you have in your list?), what will them want to buy, etc.

Plz tell me about affiliate programs what does it mean

and MLM'ers believe they own their own business? lol

I do residual based affiliate marketing :)

I do not do affiliate programs. Most legitimate MLMs forbid their distributors doing affiliate marketing. This avoids cross line recruiting.