How do I integrate a (approx.) 1000 gallon reservoir tank into an existing water well system.?

Question:I already have the tank set up and coated with a pottable sealer. The pvc line and electrical wire has been laid from pump house to the tank. I have a new pressure pump ready to be hooked up. The only major item I am missing is a float switch because I'm not sure what it is or where to get it. I have absolutely no experience installing any of this and desperately need help. My current system works just fine with the exception that it can't fill back up as fast as it goes out-- I Run out of water! I have been accumulating items and trying to get this conquered for over a year now. I'm on a fixed budget and cant hire somone. That just leaves me and believe me I'm determined to learn. Any help, advice, kick or shove in any direction will be so very greatly appreciated!! I'm at the end of my "sucker rod" Lol ;) I'll do my best to provide any other information I've forgotten to include, if needed. Thank you :)

Answers:
if your tank is a sealed tank suitable for pressure just install a pressure differential switch that will shut off the pump when set pressure is achieved if not a pressure tank you could adapt the same float system used on small sump pumps by reversing the wiring contacts