Dave,
Lets chat tomorrow at some point to see if blogging is going to be your thing.
The main thing to think about is what do you know and love?
Don't think about anything but conveying your passion. It may sound a little strange but it's really not.
To create a real interactive community of readers who had a similar interest, you want your readers to visit your site for the content. So if you focus on what you really know and love, (it really dosn't matter what the subject really) you can produce real content that has value.
We will help you with the keyword research, As we offered well over a year ago.
Also I will put up your site on my server so you can get started and we can go from there.