There are several transliteration methods. The IU Libraries use the ALA-LC Romanization Tables (Click on the Index to Languages to locate the information about a specific language):
The guides below do not use the same letters as the ALA-LC guide, but are close in sound representation.
ISO Transliteration des Kyrillischen lists the letters of Russian, Ukrainian, Belarussian, Serbian, Macedonian, and Bulgarian with transliteration and examples.
Transliteration by the United States Board of Geographic Names (taken from United States Board of Geographic Names' Transliteration Guide from August 1961).