My girlfriend and I are thinking of taking a trip to Mongolia, but I know next to nothing about traveling there, as I imagine is the case for most people. Anyone who can give advice, links, etc. would be greatly appreciated.
Where should we go?
What should we do?
What shouldn’t we do?
What should we look out for?
etc.
Bring your own vegetables… there aren’t many there. 
It has changed a lot, but a great read is Tuva or Bust [and a bonus if you find a used edition that still has the flimsy record of tuvan music.
I have to admit I want to go to Ulan Bator for the Gengis Khan festival, and visit Tuva because the capital city has no proper vowels in the name[and I happen to like throat singing, check out huun huur tu singing Chira Xur
If you visit the Gobi desert, avoid flying aboard a rickety old C-119 “Flying Boxcar” airplane. The cocky, hard-headed pilot will attempt to fly above a dust storm, but fail, and crash. Almost everyone will survive the crash, but you will be stranded with a small supply of water and food. The aerial was torn off in the dust storm (before any distress signal was sent out,) so there’s no radio communications. There may be a guy on board who will claim that it’s possible to build a new airplane out of the remains of the old one, and that he can design it and oversee its construction. This is the delirium from thirst and heat-stroke talking. Pay him no heed.
But what if he sounds really convincing?
You must still disregard him, for he will only be knowledgeable about toy airplanes.