This thing is pretty easy if you know how to do it, only takes a long ammount of time (especially if you want your font to replace the entire font in Doom, naming all that stfcn00xx shit is horribly tedious!)
1.Dan, you first need to learn about font creation in general, usage of the imagetool thingy and how to set it up correctly for proper conversion.
2.Now you'll need the quake font. Big font uses dimensions of 16 for the glyphs' height, so you'll need to make your font sheet out of 16 pixels high quake font and then convert it to a font.lmp with image tool.
3.Put your font into your wad. If you want it to replace Doom's bigfont name it "DBIGFONT". Otherwise, name it however you want and call it from a script via setfont
script 667 enter
setfont("insert quake font name here");
print (s:"This is my font, Admire");
If you provide me with the quake letters (glyphs) I can make such a font in a matter of 1-2 hours.