A decent blog on a website, one that has consistent posts and well-written, interesting content, will help you get into college. Further, the weekly discipline required is a skill you want to develop.
Blogging is really difficult. All sorts of issues of quality and originality come up, which can easily block you up and keep you from writing. Scheduling it can be hard. Just sitting there and doing it can be hard. This is not an easy assignment. Don't underestimate it.
Don't write to entertain other people. Don't write for a grade. Pick something that is bothering you and write about that. Write about problems you're having in your process. Write about your work. The students with the best blogs invariably start posts by writing about a problem, and then in the course of the blog they seem to solve the problem.
Write something useful to you.
You need to have 10 blog posts on your website completed by January 20th. Each post is approximately 400 words in length. The topic of each blog is up to you as long as it is somewhat are related, and if not that, at least something you personally care about.