The library has several excellent sets of books on dinosaurs, including some that are heavily illustrated.
Some of the best ones located in the Reference Collection on Tier 2 (but cannot be checked out):
If you just want to browse this section of the check-out collection, most dinosaur books are located in the library at QE 862 D5 (on Floor 2).
There are also some very nicely illustrated, general introductory level dinosaur books in our juvenile literature collection. They range from a kindergarten level picture book up through fairly detailed high school reading level - PZ 134.5 (1st floor).