Here are two excellent sources of information:

Shamanism of Siberia and Central Asia:

http://buryatmongol.org/shamanism-of-siberia-and-central-asia/

Shamanism – Indigenous People of Siberia:

http://www.face-music.ch/bi_bid/tengerism_en.html

The amount of information on these sites is enormous, so it is well worth checking them out!