Blogging Confuses me! Help?!?

[Insanestar044]

I am planning to start a blogging business. But i have no idea what the blog itself is going to be based on. I know its stupid but, i guess if i had to describe it .. i would like a topic that would get some traffic. Im not talking marketing or house selling. Just a small 'Entertainment' kind of thing ... i'm not sure though >.<
and how would u get traffic to your website anyway .. whats the chances of someone randomly typing 'www.Jimsplace.blogspot,com :/... no thats not mine , but im just wondering how do these blogs get so much traffic can i have some explaining in detail please, i have time ...