List of Categories sorted by Popularity?

[bluebrit]

Bear in mind that one persons list is not likely to be the same as someone else's because everybody has different traffic and what sells well for one may not for another.

Your best option just starting out would be to build pages based around something you can relate to then look at the keywords that bring people to your pages. Look at what links people click when they are on your site and then use that information to expand and build niches to suit your own traffic.