I try to convert an xhtml document, and get a warning:
prince: warning: no glyphs for character U+05D1 (and other chars as well)

However, I can see these chars when I view the document in Mozilla or in a Linux text editor, so I do have the fonts installed on my system. Why can't prince find the glyphs?

(I have Linux Mandriva)

Prince currently does not attempt to load every font on the system, only the fonts that are listed in the font-family property.

This means that if you are using scripts such as Hebrew or Chinese that are not supported by the default fonts like Times New Roman then you will need to explicitly add the font you would like to use to the font-family:

body { font-family: MyHebrewFont, serif }

(Another issue you may run into is that Prince 5.1 does not support right-to-left text, required for scripts such as Hebrew and Arabic).