Choosing which font to use in your book in no easy task. Typing a line of text and testing it in each typeface is well, more time consuming then anyone really has time for. If you want to get a quick view of what a block of text will look like, especially for the title on the cover of your book, check out flipping typical.
You enter a word, or little line of text at the top, and it displays what it would look like in the fonts you have on your machine. A small caveat, it may not grab every font you have available and it won’t tell you which to choose, but it will help in determining if a serif or sans-serif is better. Or if you should go for a bold or a slim typeface. You get the idea.