Select the edition you want to print according to the paper size you are using (both an A4 and a US Letter edition are provided in the download) and open it with a PDF reader. Print it as you would any other document. You may want to avoid printing the cover page because it will use up a great deal of black ink or toner.

I do not recommend uploading it to a print-on-demand service like Lulu. I have never tried this. I also know that the PDF output by Pages is not suitable for the printing systems used by these services because of the way it handles transparency and fonts.