Hi Nienna,
I actually bit the bullet a few months ago and created my own blogspot blog. I don't really use it to blog with the expectations of getting regular readers, but I do use it for the following:
1) Until I find an agent (hopefully this won't be much longer since I've got 2 agents reading fulls, 2 reading partials!!!), pretty much the only article on my blog is the first chapter of my unsold novel. Some agents don't want writing samples when you e-query, so I include a link to my blog in with my e-query and tell them they can read the first chapter there. Dunno if it works, but I have noticed that somebody has been viewing my profile (it shows you how many people have looked at your profile).
2) I also use it as a practical homepage. I've created links to many many agent blogs on it (among my other favorite writing websites) so no matter what computer I'm using, if I pull up my blog I've basically got my agent-hunting-dashboard right in front of me. Also, on the off chance you're directing an agent to your blog, it doesn't hurt to have a link to his/her blog on your blog. And queries aren't the only way to direct an agent to your blog: once you have a blog and you answer a question/post a comment on an agent's blog, it's basically very easy for him/her to click on your name and check out your blog.
My only advice for creating a blog is this: Keep it professional.