Ok, here's my wish - A DC for Dummies guide. Something that helps "decode" the system for newbies (numbers only derive from streetcar lines, letters before numbers are DC/MD based bus lines, numbers before letters are VA based bus lines, odd number suffixes tend to be peak only services with exceptions, etc. etc.)
Somewhere I have a PDF map I made of the Metrorail system with lines showing how bus lines could be used to ride from one station to another. I need to find that and post it.