Though on my wiki Hackey, the currently inactive admin who adopted the wiki with me, thinks that they're pretty much the same as forums.
Well, imo blogs are more for personal purposes. Hackey disabled blogs because people were confusing them with forums. Blogs are to post personal comments on the game involved (and invite replies) while forums are used to post either questions or polls (and sometimes announcements), and invite open discussion.
como q eu faço para postar minhas capituras de tela nesse site
Ummm... ok, vá para "Photos" e selecione "Add a photo", em seguida, escolha sua foto (captura de tela) e abra "More Options" no canto inferior esquerdo. Renomeie a imagem para outra coisa e selecione "Upload Photo".