I recently started playing with a band and they use one of those sound boards or whatever they are called. My amp only has 1 input though so is there a device to plug into my input that allows for 2 inputs? Ive seen ones with 2 headphone jacks but not with 2 guitar size jacks.
Are you talking about plugging into a PA? If so you can buy somthing like a SHURE SM57 microphone and an XLR cable to plug into the mixer. If that's what your talking about.
I assume you are talking about a P.A.

The signal goes to the board not from the board, get a mic, and mic your amp, and then the mic will hook up to the Board.

if you're talking about recording boards, then you will probably have to get a new amplifier with a line out cable, and then use a standard guitar cable to plug it into one of the line-ins on the board
you can mic your amp, or get a direct box. google directbox, or put it into musicians friend. lots of options and configurations.