What the devil is a blog?

I don't know how these online blog things are supposed to go. I never even heard of one until this year. Even then, it was a celebrity who had created that one, so I could at least begin to understand the appeal of reading it. But my own?

I'm not sure if they're like message boards or like a website or like a journal or like a poetry forum. How detailed and how personal do I go? Do I write about my day to day life? Am I supposed to write every day? Every week? Do I have to try and make it interesting for others to read? Entertaining? Or should I pretend that it's only for me and type what I'd type if it were my personal diary? Things like "Well, I finally killed Tom today. With a shovel. I really should've laid down plastic first."

If not, what is appropriate or entertaining for those who might stumble upon it? Certainly not junk like "I finally bought that treadmill, like it or not. It took forever to put it together, and when I finally got it running, it was so unpleasant, I may never use it again." Right?

I know a guy here at work who is madly in love with Jaclyn. It's really embarrassing. He likes to make lists, and earlier in the year, he decided to list what Jaclyn wore every day for a month, how she wore her hair, and how beautiful she was on a scale from 1 to 10. It produced entries such as:
"July 2nd; tight black sleeveless shirt with high neck, khaki capris; combed straight down; 9.4."
Now, whether I'm unhealthily obsessed with Jac--er, the person who did this is obsessed with Jaclyn or not, is this something appropriate to post as a blog? Wouldn't that make my, uh, friend look like a raving psycho?

And maybe I'm missing the point. Maybe blogs are something for children or teenagers, writing each day and sharing with their friends. Like they used to say, "If it's too loud, you're too old," maybe if I don't get it, I'm too old.

I really don't know, though. I like the idea of this online musings page. Maybe I'll try different things on different days. Maybe I'll try nothing.

Perhaps I should read a book instead.