Don’t go out looking for a “WordPress for dummies” book- it will be obsolete before it’s off the presses. WordPress isn’t that complicated and you really can’t screw your site up too badly no matter how hard you try.
The biggest mistake a beginner can make is by changing to a theme that doesn’t have a log-in button- and they can’t figure out how to get back to the dashboard. No worry here- just go to www.yourblogname.com/wp-admin and then type in your user name and password. The user name is typically “Admin” if it’s your blog.
The other place you can screw things up is under the Options menu- by changing the location of your blog. If you happen to do this, someone who knows how to access your MySQL database on your server can get in and change it back.
Other than those two issues- (and it there are others- please feel free to add comments) the most you can lose is a post or page unless your sever crashes. That’s why it’s a good idea to enable the WordPress database back-up plugin in WordPress 2.0 and back up your data to your computer on a regular basis.
If you don’t understand something- and the question isn’t answered here- you can always e-mail me the question at [email protected]Â and I’ll try to post a response soon.
Your other solution is to Google your question- more than likely someone has already answered your question online- just type in “WordPress” and “your question” and you should find an answer quickly.
The WordPress documentation on the codex http://codex.wordpress.org/Main_Page is full of good stuff and getting better every day.
And if you solve a problem on your own, and you didn’t find a good answer with Google- post it in your blog, so you can help others.