Here is a link collection of some useful blog posts about blogging when you got the blogger's block:
The 25 Basic Styles of Blogging... And When to Use Each One Slideshow
Blogging Tips - 29 Topics and Sentence Starters for Your Next Blog Prompt List
The 5 Types of Blogs That Experts Write
Educators See Also:
Transparency and constructivism, etc. (Or five good reasons to blog the research process)
ResearchLogTemplate shows a great example how one could use the category features to work and organize your research into.