This is a collection of other MLP sites that I recommend visiting.  All are well made and constantly updated.

Everybody's one stop My Little Pony Reference Site 
Dream Valley

Another good place to find that pony you need...also a great price guide!

eBay

The best place to find someone with that pony that you just absolutely need!!

The My Little Pony Trading Post

Spaced Out Ponies on Mars | Trade List | Want List | Other MLP Links
Pictures | Marvin Stuff