Ok...I don't know if I can/should do this w/ JavaScript on the client or can/should this be done on the server - and if so what language would be best?

Here's my goal:
I am asking users 4 questions - depending on the one selected - that answer creates a profile and that profiles stays with them throughout the site.

E.G.; if (women under 30) is selected this information will stay on the site throughout w/ content detailed for this group.

What is the best method for this?

Thanks....