Please note that if your blog is not on the subject of weight loss, or activities that can aid in weight loss (such as an exercise blog), then it will be rejected. After your blog has been accepted and is listed it will be given a screenshot, this service is provided by thumbshots.com, and I have no control over when your thumbnail will be updated.
When your website has been approved, you may want to promote it to make sure your fans know to vote for you and get your listing up the rankings (but please don't ask them to vote others down just to make you look good). Twitter, Facebook, blogs, and your newsletter are a great way to do this. I have made some banners that you may want to display on your site telling people to vote for you, promo banners are on this page.