It took me a while to figure it out too, especially the personal blog layout - I still struggle with that. But basically just reblog shit. Fool around with it. You'll figure it out If I can, you can!
Ah. I see what you mean. Well a few people I know in real life use tumblr, like the friends that I've met through Mibba. And a few of my friends from work go on tumblr because they follow this "you know you're a nurse when" blog, which I follow too because it's obviously hilarious