Hi Veda: There are many ways to do what you are trying to do, but my first order of business would be to secure that opening! Your greatest nightmare is a small child, who has seen you around that area, come over when you are away and manage to get
the wood off the opening and fall in!
To keep it secure, I think I would build a cinder block or brick rectangular wall about 36 to 40" high around the opening. I would then make a double thickness 3/4" plywood cover, held in place with anchor bolts in
to the blocks/bricks to securely hold this in place. Then put a lockable trap door in the middle to work out of. Now you're secure.
Quite honestly, the easiest and cheapest way to get the water from the well to your bucket is an electric pump and a long
garden hose. The motor (a 1/2 or 3/4 HP single phase 120 volt should work as long as your lift isn't over 50 feet or so) can be mounted on a small concrete pad (say 12"X12") poured next to the well, held down with anchor bolts, and a plug for an extensio
n cord. A hose fitting can be installed on each side of the pump. Or, you can just go to your local farm supply store or even home improvement center and ask for their advice on the correct motor/pump combination they probably have in stock.
You could h
ave a custom metal A-Frame made up with hand crank, long rope, etc, but it would be expensive and a lot of back breaking work.