Hi mcharvet,
Most good web hosts nowadays can install a blog script within a folder in
your domain. That's how people get their blogs in their domains. All it takes
is a trip to your web hosting account control panel and clicking a button
called "Install blog" for example. You will be asked where you want it installed.
You can choose to have the blog installed in a folder called "blog" for example.
And that's pretty much it. After clicking a button, you'll have your blog
in the "blog" folder of your domain.
You can then access an admin area, similar to the one you access at
Blogger.com to add, edit and manage your posts.
Templates will depend on what type of blog script you have. A popular
blog script used around the net is WordPress (
http://www.wordpress.org).
With WordPress, there are thousands of templates available that you can
use for free.
Hope this makes things a bit clearer for you.
- Bina.