I had browsed through a few before when posted in AncientScripts group from your post, and now there are so many fantastic ones added!

In just one link alone, Fonts-Ancient Scripts offered up really fantastic information like Sumerian Script detailing possible origins, appearance, translations you name it. And don't forget to check out their Extras page with dowloadable games and fonts! And this is just one link, what a wealth of informative sites you offered, Rest, much appreciated!