Our family has a beautiful tree in their back yard that changes with the season and is strong enough for the kids to swing from and provides great shade in the summer. But the tree is constantly weeping with sap from a stump of a branch that they had cut a few seasons ago. This sap occasionally gets on hands and clothing and also makes a dark sticky mess where it drips off the tree.
A burlap sack tied around the tree where it leaks sap is an easy solution to prevent further sap from dripping and WD-40 has a reputation for removing sap from almost anything. If sap gets on your car you should first apply denatured alcohol and let it work its way into the spot and then just wipe away. To clean sap from your hands try rubbing mayonnaise on them then clean with soap and water.