I would suggest that you stay on the West end of the lake (State Dock is considered "West end"). If you are looking to be in the middle of a party, then you will want to go to "Harmond Creek". Once in Harmond, go to "Jack's Branch" and tie-off to the beach about half way into the cove (Jack's Branch). It may be getting crowded by July 4th but this is THE party spot! Of course the Water Patrol will make a few cameo appearances each day.
Now, if you want a more private experience then give "Difficulty Creek" (next door to Harmond) or "Wolf Creek" a try (which are all East of State Dock but still considered West End). If you head West (towards the dam), there are some nice islands to beach and tie-off on also. I would not choose a spot on the main lake unless it is protected, such as behind an island. Coves are the hot tip for calm private fun. Since the water level has been brought down, this lake has taken on a whole new face. There are large beach areas and islands that did not exist before. Absolutely beautiful!
Also, I hope your are taking some ski boats so that you can come back to the harbor at State Dock and Jamestown marinas Saturday night. They put on a fireworks display over the harbor at 10 pm cst. Nothing like watching fireworks at night from your boat, great way to end a day.
Where ever you end up, have a great time on the lake. It's hard to have a bad time boating on Lake Cumberland. Bring half the clothes, half the food, and 3X the alcohol, lake rules

(Caution: all adult beverages in coolies or plastic cups NO exceptions)