Make sure any US currency you take with you is no more than 2 years old and unfolded, un-torn, and un-marked. Or they won't accept it, even in banks. Lots of counterfeit money there.
Get your Tughriks from an atm. That is usually the best exchange rate.
Most medium to large towns have internet cafes. Small towns won't. It's surprising how much cell phone coverage there is.
There is a small paper map they have in a shop in the international arrival area that is better than most. It's about $10 (or was 3 years ago).
These guys have a decent reputation for rentals and tours. Prices aren't posted on the website anymore, but they were competitive a couple of years ago.
You see the Chinese bikes in all of the towns, but we never saw one very far from a town, and they aren't really enduros.