In doing some online research for an upcoming project, I found this site. It has some great links, and an ungodly amount of information on writing systems. There's a bit of a navigation problem in that if you really want to get to the good stuff, you have to click on the writing systems link, then scroll all the way down to the taxonomies at the bottom of the page. Click one of those to find a specific writing system.

I've had an interest in writing systems since I was an undergrad. One of the five people in my Germanic Linguistics program showed me a book he had been working on since he was a child. It was a four inch thick binder containing hand written, photocopied, or printed samples of every writing system he had been able to find. It was the most comprehensive collection of writing systems I have ever seen, even including fictional writing systems like Klingon and Elvish. Of course, I can't remember the guy's last name, so I can't even google him.