Brenden's advice is what I would suggest as well - there really is no substitute for seeing it in practice on the default Corporate site, if you have it installed.
Repeaters are pretty much exclusively used to display both the summarized blogs in a list as well as the actual final individual posts (Selected item transformation).
I would also add that the developer's guide has an excellent section on the blogs module, available here: http://devnet.kentico.com/docs/devguide/module_blogs_overview.htm