Never underestimate the power of typography. If done correctly, fonts are an easy way to enhance the feel of your book. Don't write an entire 80K word novel about an Egyptian adventure in Papyrus. It's great for the header and footer, but not the text itself. That's too much on the readers' eyes. Go for the serifs. They are considered easier for the eyes to follow, therefore quicker to read.
Five Interior Book Fonts and where to get them- http://www.thebookdesigner.com/2009/08/5-favorite-fonts/
If you're looking for display fonts, a great website that hosts a ton of them is