Well, I'm still learning all about this webcomicing business, but pretty much what I did was
a)start setting out a design, and thinking of some gags, actually based around myself and my flatmates
b)When I had a few strips made, put them up on my livejournal for comments
c)Put a few jokes up on one of the forums I frequent, mainly insulting the n00bs, spur of the moment thing, with a link to my livejournal for more comments.
d)Once I thought it was worth it, and I was doing a new comic every day or two, I set up a keenspace account, that you can find at http://tog.keenspace.com
, and made sure all the people who read it new where it was.
e)Told a few people around the livejournal communities about the comic, set up a hit counter, set up a buzzComix account, and watched the votes come in.
This has taken me, within a couple of weeks of setting up the keenspace account, to place 150 on buzzComix at the time of writing. Not too shabby methinks.
[Edit]Not really trying to plug it, I just thought that my advice would have a bit more oomph if it had proof.