New to Blogging --Damn Spam

Well, I've been involved in discussing blogs for a few years now and thought I would try one of my own related to Mass Communication-based conferences I attend, starting with SWECJMC 11/3-5 in Colorado. My first evaluation is to wonder how the spam shows up so quickly, and to ask if anyone knows how to keep it from showing up as comments when the comments are not specific to the blog and clearly are just people looking for free advertising and such. I guess I solved the problem by setting it up so the moderator has to approve all posts.