If uploading a PDF to Lulu for your book, you may use any fonts you like, but you must embed the fonts in the PDF. Keep in mind, that you may not have the printing rights for a font and that some fonts are only screen fonts and can't be used to print. With these kinds of fonts, you will not be able to embed them in your PDF or if they do embed, they won't print correctly.
The easiest way to ensure your PDF prints the way you want with the fonts you want is to use Lulu's Adobe Job Options on the bottom of this page.
The other option is to adjust the settings yourself by going into the PDF settings.