Correct Font Size for a Novel?

I've moved my novel from MS Word to InDesign.  The typography is greatly improved.

I'm using a Mac Font called Baskerville. In MS Word 11 point Baskerville seemed about right. When I print out test pages from InDesign, 11 point Baskerville seems smaller - in fact, too small compared to other hardback and paperback books on my bookshelves.

Is there a rule of thumb in terms of selecting a correct font size?  My book layout is 5.25" x 8".

Thanks very much in advance to all for any info.