I went to the University of Oklahoma.
It is very easy to find whatever you're looking for.
1) Explore campus a lot, even if you don't really have a purpose. There were things that I was finding my third and fourth years. You will eventually learn where all of the buildings are and the random class gifts and old meeting places and anything else cool your campus may have.
2) People will be helpful. "Hey, you do you know where the engineering building is?" You've found your answer.
3) My school had maps everywhere and online if all else failed.
My only complaint: Some of our buildings were too small for their original purpose or got re-purposed for other reasons. They became a mishmash of offices, class rooms, and every other function you can think of. If you were looking for a building by type (say, engineering), it could be difficult, because a few different buildings might all have overflow for that building.