The home sites for some text-only resources are listed below. When a double site is specified, the first one is the true one, useful when you look for alpha version, and the second is the widely mirrored one. When a single site is specified, it will include alpha releases and is a widely mirrored one.
As usual, the source code is the best source of information, and the kernel is the place if you are going to code some low-level software for the console. The kbd package is another good place to learn things. Remember, however, that any console-bound program is not portable, and a portable solution is better, if available.