If you are planning to write a book, these useful guidelines about font names and font sizes from CafePress will come handy.
1. Make sure your cover typography stands out sufficiently to be read; almost everyone really does judge a book by its cover. On the average, a bookstore browser spends eight seconds looking at the front cover and 15 seconds looking at the back cover.
2. The most widely used typefaces for book body text include Baskerville, Bembo, Garamond, Janson, Palatino, and Times Roman (although this more of a newspaper font). Sans serif fonts may be difficult to read for an entire book.
3. If using a sans serif font for body text (Helvetica, Arial, Verdana, Tahoma, etc.), do not use smaller than 8pt. size. If using a serif font for body text (Berkeley, Palatino, Garamond, etc.), do not use smaller than 10pt. size.
4. Typography convention holds that sans serif faces should be used for display headers and book covers while serif typefaces are used for body text to ease readability.
5. Use larger point sizes for display headers, and much larger point sizes for your book’s cover copy. Link.