Appropriate length
A blog that just a few sentences long will likely not be featured, as it would be lacking in content, but a blog written like a novel may be too long to hold reader interest. Try to aim for content that will take about 2-5 minutes to read. If your content will be much longer, there is nothing wrong with breaking it into chapters.
Be sure to check out the Cerberus Center for more info and a table of contents.
Thanks for reading!