There is not much to explain:
blog_Config > Blogs and Users (eventually, users will be seperated)
blog_Content > Posts, Articles, Comments, Trackbacks (each has its own PostType) -> All map to .Text's Entry object
blog_LinkCategories > storage for post categories, article categories, link categories, and image cagegoreis (each has its own CategoryType value)
blog_Links > Individual links or the ID's to posts/articles for a given category. Its uses an FKey for blog_CategoriesID
blog_EntryView > Views for posts (counts and agg views)
blog_Urls > Unique referral url's
blog_Referrals > counts for each post's referrals
As for SP's, two many to list individually. The good news here is I have been doing a lot of cleaning here and over the last couple of days I have eliminated about 30 of them.
-Scott