The easiest way to start a blog is probably through http://www.blogger.com and follow the instruction for your free blog.
Keep it local! I see a lot of agents posting about generic/national real estate statistics, when the people they're trying to reach dont have the same interest in real estate as they do. Write about your town, restaurants and big events. If you can get a couple quality posts up a week you will notice the traffic increase in less than half a year (sounds long but your marketing for the long run). Also consider paying local writers off craigslist to talk about local stuff on your blog. Trade links with local bloggers.
I use "Blogging Systems" for my blog but like I said, you can readily do this yourself. It is part of Web 2.0 which is "social networking" and is the basis of Trulia voices. I spend too much time on this site. I should be lead generating and not getting roped into some of the more outrageous threads on this site!!