Make sure to download the macgs-5xx-fonts.sit.bin archive.  The xx refers 
to the particular release (currently 510).  

You only need to download the fonts once, as they are the same for all 5.xx 
releases of Aladdin Ghostscript.  That is, if you upgrade to a newer 
version of MacGS, you do not need to re-download the fonts. 

After decompressing the fonts, place the fonts folder "fonts" into the 
folder containing the MacGS application.  Make sure that your fonts folder 
contains fonts, and not a sub-folder.