If you use make old config it will prompt you for everything new thats been added to the new kernel since the kernel you got the config from.
make menu config gives help on each option.
If you have a kernel that works now, do the make old config thing and just go through the new options.
I am not smart enough to make one from scratch that actually worked...I just cheat and use huge.
The link at the top may help point you in the direction of the docs you need/are looking for.