I’m not going to beat a dead horse here.
If you want a blog then find a suitable web host, install and Voila! You have a blog.

Do with it what you will.
Write, add pictures, video, podcasts,…. whatever you want. The possibilities are limitless, yes, literally limitless.

Anyways, like I said, I’m not going to beat a dead horse here.
But I do want to point out some tips I have found, some useful links, and just great stuff that will help you to create a great blog, add great content, professionally publicize your blog and get visitors.

I use WordPress for blogging, it’s even used on this site.
http://www.wordpress.org
I suggest joining the community so if you have questions or problems you can easily, and usually quickly, get some help.

So, after you’ve found a web host you need to upload, or install, WordPress. Then find a theme you like and install that (usually ftp it into your /blog/ or /wordpress/ folder into the right directory, login to admin and install themes, plugins, widgets and create pages and posts.
Here are some helpful links for stuff:
WordPress.org Community
WordPress Plugins
WordPress Themes
Favicon Creator
Stock Photos
Stock Photo Exchange
Google Trends
Ping Google

Also, keep an eye out for great sites that have tips on the initial setup of your blog. No matter what theme you select there is a lot of work to do under the hood of your new blog site. I’ll list them as I find them and feel free to use the comments area to add the sites you know of, even if it’s your own!