are they free?
I think the best free blogs are from WordPress.com Get a Free Blog Here. It's a free open source software and there are lots of free templates you can use to customize it. Your domain would be xxxxxxx.wordpress.com if you had this blog. (So it's like blogger/blogspot, I just like the software better personally.)
can people find them if they google you or your name?
If you want your blog to remain anonymous, you could use pseudonyms, initials, first names only, or anything you want. Lots of bloggers do this.
can you tell who looks at it?
You can easily install widgets that help with this. Like someone said above, StatCounter is a popular free one that tracks the last 500 visitors at any given time. It will tell you IP addresses of visitors, but not their names though (I'm not sure of this)
how many hits?
Also on StatCounter (or SiteMeter, or Google Analytics, etc)
is it hard to maintain?
I think it's more of a habit than anything. You could try it out for a few weeks and see if you are good at keeping up with it. It's more fun once you start getting comments. It's like you need some momentum. Who would you want your readership to be?
You could start by finding 5-10 blogs to read regularly, and then start commenting. If you feel like you have a lot to say to the comments and topics to write about on your own, maybe the next step is to get a blog yourself.
Here is a good article:
Be More Than a Blip in the Blogosphere - washingtonpost.com