I have an X11 program that allows you to set a font.  It apparently accepts the 'standard' X Logical Font Description.  This notation is fairly obscure, and while the document I linked to mentions it, it doesn't actually describe the syntax.  Is there some kind of font picking tool that will provide a list of valid fonts, and allow me to picket a font from the list, and specify the sizes and such, then print out this notation?X Logical Font Description  X11 core font instances are usually specified using a notation known  as the X Logical Font Description (XLFD). An XLFD starts with a dash  `-', and consists of fourteen fields separated by dashes, for example:-adobe-courier-medium-r-normal--12-120-75-75-m-70-iso8859-1
Deciding on a font, and determining the proper notation
x11;fonts
xfontsel lets you browse through the available X11 fonts and provides rendered previews so you can see what they actually look like.  It's fairly plain-looking and basic but it is provided with most Xorg installations by default.