Jeff,
You'll need an audio interface for both the keyboard AND the guitar, if you wish to record audio from both. I assume that you will.

An audio interface like this will give you Ins and Outs for audio.

http://www.pgmusic.com/cakewalkua1g.htm

However, it will only give you two channels, and you'll be using at least three inputs, a stereo input for the keyboard and a mono input for the guitar. You can switch cables going into the interface, if you have a "Direct In" box for the guitar. You might also consider an audio mixer like this one:

http://pro-audio.musiciansfriend.com/product/Behringer-EURORACK-UB802-Mixer?sku=631238

You might be able to plug the guitar directly into the mixer, but if you have an effects box, there should be a line output from that which would work better.

Then, plug the keyboard into the mixer, the guitar or effects box into the mixer, and then the mixer into the audio interface.

Gary

I'm blessed watching God do what He does best. I've had a few rough years, and I'm still not back to where I want to be, but I'm on the way and things are looking far better now than what they were!