cgoban -help
One switch that you may want to use is the cgoban -fontHeight size switch. This switch changes the size of everything that cgoban draws. The default is 12; running cgoban -fontHeight 14 will make the board, etc. larger, while cgoban -fontHeight 10 will make it all smaller.
Any of the command line switches can be set instead with an X default. For example, if you want to set black and white to be the default mode, you can run complete goban with cgoban -nocolor, or you can add cgoban*color: 0 to your X defaults.
Cgoban will store a new .cgobanrc file every time you run it. In this file it will save the current state of cgoban. This is handy; you don't normally have to set command line switches since cgoban will remember them in the .cgobanrc file. However, it is possible that the .cgobanrc file gets some bad data in it. Just delete the file and then you can start from scratch again.
http://cgoban1.sourceforge.net/