Ten Ton Hammer just released a guide to the mounts of World of Warcraft. Although it sadly lacks screenshots, it provides an excellent summary of the mounted experience.
Here is what you will get:
- Speed information
- Skill level and cost breakdowns
- Mount restriction details
- Lists and locations of faction-only mounts
- Reputation and discounts available
- Class-specific mount information
- The low-down on mounts that are obtained through the Trading Card Game.
Although, if you are looking to find specific information about the reputation grinds and drop rates on various rare mounts, neither guide will suffice. For the truly in-depth, expert knowledge, I recommend taking some time (up to a few hours) perusing Wowwiki's mount pages.