Get people in real life and online to help you, I find a lot of artists are shy and don't promote themselves in RL. Some times all I have to do is draw in at cafe and people come up to me and say they like my work, and sometimes the convo reaches long enough for me to hand them a business card. Just tell all friends/family/random people you can strike a convo wih you are doing this and get word to spread. Also conventions are good places, find an inexpensive one to start.
Look up free host sites that fits your comic well, and you feel the ppl will welcome it.
I'm trying to figure that out myself. One thing you might try is putting sample chapters on various free comic sites like The Duck and Comic Fury. Another is offer free issues in electronic format. And put it up as a free download on torrent sites. All web comic creators fight one thing: obscurity. If you've got the money you can also place ads on Project Wonderful which is an ad-stream advertising company that caters to webcomics. I've actually found a few comics that way.
Be active across multiple social networking sites. Make an account on twitter, tumblr, facebook, etc. Use them to promote your work. Find places you can purchase advertisements if you're willing to go that route. If not, ask your friends if they would mind advertising it on their pages or in their sigs or something. The biggest thing though is to just be active with your followers. Another important part is a regular update schedule. If you update sporadically, you'll lose viewers. Try to keep a schedule of uploading pages once a week, or every couple weeks, or whatever works for you.
I've been given this advice as well, and it begs a very important question...
How exactly will you get people to notice you... On those sites? For those of us ForeverAlone types, we have little in the way of expanded advertising. No personal friends we can ask to advertise for us, no contacts to spread the word so on and so forth.
This bit of advice always left me scratching my head for the above reasoning. I know advertising wouldn't be easy regardless, but it seems like we'd have to go on advertising campaigns to promote another advertising campaign to promote another advertising program unless one has a large circle of friends or contacts willing to flail your site's address around for you.
Marketing is a personality contest as much as anything. If you can't make people like you enough to tell their friends about you, then you're just not going to succeed in marketing yourself. You have to get your ass out of your hermit shelter and make contacts. That's why they call it "building a network" and not "poofing a network into existence." It takes effort.