There doesn't seem to be much that isn't covered as a topic for a blog, so why not jump in with both feet and blog about your business and how to be a successful MLM marketer. What a tremendous vehicle for telling people what you are doing, how you are doing it and all about your team and training. You can also add pictures, product descriptions, and yes, even comments from other people.
Blogs have been around since early1997, but really took off in popularity when automated publishing systems were introduced - ie. Blogger at blogger.com. Just so you don't get confused, stick to the term blog, rather than the other alternative "weblog" as it means a server's log files. By 1999 there were 23 in existence, but it didn't stay that way long. Blogs and blogging mushroomed rapidly until it was almost impossible to keep up with them. Those who designed software got into the mix and came up with even more ways for people to publish their own blogs.
The history that's important for you to know, because it directly relates to what you can do with your blog, is that original weblogs were link-driven. Today's blogs are also link driven and there is your key to the success of your MLM marketing blog. Seek out unusual links, interesting links, teaching links, and learning links for your blog, and add you own review or commentary to them. Send your blog link to existing customers, potential customers, your team, even others in your up and down lines. You'd be surprised at the exposure you'll get so long as your blog is well done and doesn't come across like one large advertisement for your business.