My kids love books. We go to the bookshop most weekends to browse, read and buy books for them. I love it when I get a good bargain in books ie finding a cheap but good book. A cheap book that is printed on cheap paper may be much better than the expensive colourful one printed on glossy paper if the content is good. With books, its much better to look for content rather than appearance.
My kids don't go out much or travel much because we don't but the books provide them with a lot of exposure. It is also easy to explain to them about the things they are going through by reading books. There are books on potty training, overcoming shyness, sharing, bullying in school. These are things that they relate to and when they read a book it helps them to understand the situation better and feel that they are not alone.
For example to overcome my girl's Nighttime Fears, we read a delightful online book called The Monster on Top of the Bed from Lets Be Creative.org. The ebook is also available on CD and hardcopy, you'll have to visit the site for more details.
The book tells the tale of a monster who lives under the bed who believes that the girl sleeping on the bed is a Monster on Top of the Bed. My girl was really amused to think that the monster would think of the little girl in the book as a monster. These kinds of books help to allay the child's fears because it helps them see things from a different perspective and in a way that they would understand. The monster becomes less frightening when she realises that the monster is equally afraid of the little girl as well.
The exposure that my girl gets from her books surprises and amuses me. Sometimes when I ask her where she learned a certain word or where she learned to draw a certain picture, she'd go "Mummy, its from xyz book!" Then she'd run to her bookshelf and pull out that book to show me.