cghub.com is another good site - which is set up to be both a networking site for artists as well as an online portfolio. It's well respected and has a great clean look to it. I'd say that's the easiest way to create an online portfolio.

I'd also look at blog software - blogspot or wordpress - as they are well organised for this sort of work. Finally, there are many website templates that are more or less designed for this sort of work. I looked into http://www.squarespace.com/ a while ago and it looked like a pretty good solution. However I eventually coded my site myself by hand.