Scroll down the home page to get to the region and country divisions. This is the premier site for European primary sources. You can even get the Declaration of Arbroath. The Scottish Cultural Resources Access Network is only in its infancy, but is quickly becoming the place to find images, text and sound regarding Scotland's past. While it is subscription access to the full database, it is possible to get thumbnail impressions of the images without being a member.
Schools are the biggest group of members.
One of the sites for medieval history with a strong emphasis on images and primary texts. It can be sometimes be difficult knowing which section to go into but there is a keyword facility. You can also search the Argos Web site from here. This is one example. Again strong on listing the sites which have primary sources.