Sometimes, the fonts used in the files submitted to the server are not on the computer operating the server which causes your book to be printed incorrectly. Embedding a font is not always necessary for desirable printing. Embedding your font will prevent your book from being read incorrectly by the computer by changing the way the file works under the hood, your book's appearance will not change as a result of embedding the font. To embed your font you must use a distiller.
A distiller is usually available in many Adobe programs. To open the distiller, find the tools bar at the top and select distiller from the drop down list.