Paul,
I am by no means an expert on squirrels, but where I'm at, when it's still this warm, I have the best luck early in the day. About 15 or 20 minutes after first light until about 0900 is when they seem to be most active. The ones in the pics were all shot out of trees, and distances probably averaged at around 15 yards. As for points, I have always used mostly homemade points that consist of .38 casings and bear bleeder blades(ala Tom Mussatto), but usually have a bit of a selection in my quiver. Right now I have arrows with the homemade heads, some with Ace Hexblunts, and a couple with Gamenabbers on them.
I had never used the Gamenabbers much, but right now am pretty impressed with them. I used them on two of the squirrels I got last weekend and they worked great. The head either passed through or stayed in the body of the squirrel (which makes for a much easier recovery), and both of them died straight away. Besides that, I missed one shot and squared a cedar tree; The shallow point on the Gamenaber didn't penetrate at all and just bounced off. They're not too expensive either, at about 8 bucks for a dozen.
Good luck on the hunt! With a bunch of friends, some bows, and some bushytails, you're bound to have a blast!