The Society for Creative Anachronism is an excellent resource for medieval studies. They focus on the European Middle Ages, but sometimes they have articles on their sites that pertain to other areas before/after this period as well.
This particular site we are checking out contains some great articles about heraldry and naming. http://heraldry.sca.org/heraldry/laurel/names.html
The articles are broken down by countries, such as England, France, Scotland, Ireland, and even a few on Arabia/Middle East.
On the bottom, there is a link to the Educational Articles which include lots of good stuff on Heralds and Heraldry.