When and how a programmer should start own business? [closed]

Question

The title says it all but here's some explanation of what I want to know: Let's suppose a programmer has around 5 years of experience in multiple, mainstream languages. Also suppose that the programmer has worked in different positions from junior developer to senior s/w engineer to a team lead. How would he know this is the time to stop working for others and start his/her own business. How important the technical skills and requirements are in addition to of-course financial requirements.

The second part of question is, if he decides to role own company, how he should take a start?

Ok, here's some more info: I am single, have no expenses other than my own mobile bills and university dues. Also there's no house rent for me since we have a joint family system (this is not only common but also appreciable in my culture and community).

I noted that most people have supposed that I want to build a new product or web site. While I appreciate getting your ideas on this, can you people also throw some light on another aspect? What if I would like to build a new, small software shop (or software house as we call it here)?