I don't know Cat well enough to give you the scoop on the best locations, but I have made them at Hen Rock several times. I've also had them come up thick in West Cove.
It's not that complicated. There are no absolutes, but I've usually made squid in depths from 70 to 120 feet. (I have had exceptions on both sides of this range, but that range is the most common for me.) I've used the Fluorescent 48 inch "green magnets", I've used the cheapy small submersible lights, and I've used the big Halogens above the water. All will work, but as a general rule, more lights better.
I like to use a small light in conjunction with a larger one so that I can move the small light to lure the groups of squid into my crowder.
More often than not I fill the tanks with squid jigs (rather than a brail or crowder) being used anywhere from just below the illuminated area...all the way down to the bottom...they are where you find them and it helps to try various depths.
If they come in really thick it helps to have a crowder. I made mine out of two twelve foot lengths of Calcutta cane, and some weighted net material. If the squid get thick you drive the netting straight down along the side of your boat and then come up under them with the crowder. Once you have a bunch in you use your brail net to transfer to the bait tank.
A good color meter helps a lot. On mine they look like a blue line on the bottom. When they get thick you see it on the meter in various colors depending on the density.
1st and foremost is location. You can't catch squid unless they are around. Right now most of the commercial vessels are making bait closer to Empire Landing than Long point or Hen Rock. If I were going I'd also want to setup while its still light so that I could look for birds and other sign. Until the squid really ball up, the small schools will initially show-up as either pale blue or green marks in 12-20F of water. Also look for a blue-green fuzz along the bottom which are egg sacs and dead squid.
As soon as the sun goes down get your lights out and enjoy a cup of coffee while putting on slickers (see below). I'd also recommend using a multi "hook" squid jig bait rig and gently pull up and down at various depths until the squid begin to float. On some nights jigging is the only productive method.
If light boats are around get at least 1/4 mile away; in most situations you can't compete with their lights. If you see no sight a couple of hours after dark and you see no commercial activity around, you might want to consider a move!
For small amounts of squid a large bait transfer net is great. However, if the squirts float a brailer is the only way to go. It takes two individuals and you'll feel like you're in a slapstick comedy until you get your technique down, but it's a very efficent technique.
Finally, WEAR SLICKERS, DECK BOOTS and old clothes. The nets hold a lot of water which inevitably drips on your clothes. Add a little squid ink and you've got a mess. Trying to enjoy yourself in wet clothes isn't my idea of fun. I'd also bring a complete change in case its needed.
One final comment: go to Mark Wisch's squid seminar next February. It's an annual happening and you'll get some great tips as well.