I'm also looking into doing a blog tour. Those cost, but not all that much. Depending on which package you buy from where, your tour can last from a week up to a month or more. The number of blog stops changes according to the package as well. What you do on each blog stop varies from an interview to a guest post to a contest or giveaway and probably some other things I'm not thinking of. Most of the companies who run blog tours also ask for blog hosts, so if any of you reading this are bloggers, check it out. It helps fill out the blog without you having to type your fingers to the bone.