Here is a great website for all the mount collectors.
http://simplearmory.com
Put in your realm and character info, Click on the "Collectable" tab on the top and choose "Mounts". This will show you all the mounts you have and the missing ones. The best part is if you check mark the "Show Planner" box. It will automatically set up a route of travel for you so you can just go down the list from site to site for the mounts. It also tells you what level of difficulty the instance needs to be on for the mount to drop.
