As far as knives for skinning squirrels, any sharp pocket knife will do, but I also prefer a lock blade. I've bought a number of lock blade, small pocket knives from Smokey Mountain Knife Works w/ their store brand, "Rough Rider." This is one of my favorite as it has two locking blades. For others similar to this, go to the link and click on the tab "Similar Items".
OTOH, by favorite squirrel skinning knife is a fixed blade, not a folding blade. Guess I'm getting lazy, but fixed blades are easier to clean and dry. My #1 knife is from www.agrussell.com. I think they call it a "Camp Knife."
My #2 squirrel knife can be found all over the 'net by searching for "caping knives." Here's one example.
Good luck. Buying a new knife (and breaking it in) is one of life's joys.