How do I set up a simple event photo booth with fixed lighting and camera settings?

I did a quick photo booth for my wife's bridal shower. The setup was for it to be staff by someone simply making sure everyone was in the frame, pressing the shutter, and making sure the strobes didn't go to sleep.

What type of lighting setup would be needed?

You'll ideally want a 2-3 strobe setup. Umbrellas are ideal for diffused light and multiple subjects. Shoot for strobes at 45 degrees on both sides of the camera placed a little higher than eye level. White background. Either put a third strobe on the background to blow out the white, or bring the subjects away from the background enough to have very soft shadows. Ideally, place the backdrop strobe in a way that will reflect off the background back onto the subjects.

What camera and flash settings would make sense for the various subjects?

1. 1/250 shutter for the fastest shutter with a strobe. This should not change.
2. Start your camera at 4.0 or 5.6 aperture, ISO 200 or 400.
3. Set your primary flash to manual at 1/2 or 1/4, zoom strobe and camera appropriate to cover studio area.
4. Test shoot with subject. Check to make sure your primary strobe is easily overpowering available light to avoid color cast.
5. If not, increase ISO. Repeat until you reach your comfort level with ISO, then increase flash power if necessary.
6. If you start with default settings and find you are easily overpowering with flash, start increasing aperture until you get to roughly 8.0, then start decreasing flash power if you still have extra room.
7. Once you're comfortable with your primary flash and camera settings, set up your 2nd strobe on the other side of the camera and start at 50% of primary flash power. Adjust until you have a subtle shadow on secondary flash side.
8. Make sure your entire range of studio space is evenly lit, adjust as necessary.
9. If available, place backdrop strobe and set power to blow out backdrop and reflect a little back to the subjects.
10. Shoot your 18% grey card and you're set!

Can I leave it in manual mode all night and only have an attendant press the shutter release?

The attendant should monitor the images to make sure background is blown out and strobes continue to overpower available light. Other than that, it's very straight forward and they should focus on the clients having fun!

Other

Very basic explanation and there are of course plenty of disclaimers I could put on here (unable to overpower available light, triggering strobes, color cast, etc), but those are all addressed elsewhere. Have colorful props and an attendant that's a people person and can get people to do goofy things.