Here are a few links to websites that may prove useful in learning the Mongolian language:

http://www.lexilogos.com/english/mongolian_dictionary.htm

http://www.omniglot.com/writing/mongolian.htm

Mongolian Cyrillic Character Transliteration Utility

The Mongolian Cyrillic Character Transliteration Client is a great freeware tool that can be used to quickly convert text to or from Mongolian Cyrilic Characters. It can be downloaded by following this link.