LakeBaïkal is a freshwater inland sea that isaveryholyplace for the Buryat and a priceless natural work of art that should be preserved at all costs!
Try reading "The Consolations of the Forest" by Sylvain Tesson before you set off for the lake and above all...go there in the summer! You should also make a point of staying with a local on Olkhon Island.
Just about any journey to Baikal means passing through Irkutsk. It is the biggest town in the region with around 600,000 inhabitants. I arrived there by plane, only stayed for a few hours and felt very disappointed. It's a dynamic town that is popular with back packers.
The lake and its surroundings have a plethora of sporting activities to offer: fishing, walking, cycling, horse riding, boat trips, swimming, diving, canoeing, etc. And, of course, if you are lucky enough to go there in summer, you can sunbathe on the pretty beaches.
In winter the must-dos are crossing the lake on iceskates or in a snowmobile, or making a hole in the ice with a chainsaw so you can go fishing.
Some people live in the isolated hamlets and cabins around the lake. Experts can go it alone but the region is very wild and isolated. I think in this region it's essential to use a local agent to organise your activities professionally and safely.