Rigging Live Squid

High,
Yes it is possible to keep them alive. Just make sure that you change the water often. The best way to rig them is with a live bait hook right through the aft end of the squid. They can still swim a little but they have an injured and vunerable look to them, that yells "free meal" at any passing fish. OTOH I have had live squid baits in the water and caught all of the tuna on butterfish, so you just never know.

High,
You really don't have to hide the hook in a live bait. If you try you'll kill the bait, which kind of defeats the purpose. I've kept them alive all night in a five gallon bucket. Just dump another bucket of water on them every five to ten minutes.

High,
Make sure you bring a bait net. They can be really tough to catch if you give them a little room.