[HELP] Commands with arguments, YAML write/read

Can anyone either help me or refer me somewhere where i can get help?

My Problem:
I'm trying to create a plugin, i need to accept a command with multiple arguments (EG: /verify set [String]) and for some info (the string entered from /verify set [String]) to be stored into a .yml/YAML file. i do have a "base" bit of code but i keep getting stumped.

Thanks in advanced.

UPDATE: i have the command bit "kinda" figured out, i just need to try to find a good .yml reader/writer, any tips?