You probably have a jet pump which pumps water down one pipe into the well where, at the foot valve and by venturi action, it shoots a greater volume of water back up the other, larger, pipe.
You need to prime the tank with enough water so that it will not be pumped dry before the return water comes up from the well to fill it.
Priming the line from the pump down to the well at the last second before turning on the pump, if there is a convienient priming port available, will help.
Having a faucet open until the water starts running will also help by reducing the backpressure.
I'd be prepared to do this more than once, in case it doesn't prime the first time.

Randy,
I dont think it is a jet pump - i'll tell you why and you can tell me if my assumption is correct.
there is no pump in-line with the system; all there is is a pipe coming out of the ground (about 20' from the well head), into the cabin, is tee'd (if i am remembering correctly) to a pressure switch, tank and line. thats it. nothing is missing from the system that i can tell, some of the interior pipes are burst from freezing but other than that it doesnt look like anythingwas taken out/away from what is there. K

Not knowing what the manifold pipe is made of, I'll assume it is galvanized so as to address worse case scenario. The same with the stem attached to the pressure switch. These two items may be rusted. I would remove the manifold, make sure it is clear. The same with the nipple going to the pressure switch. Make sure it is clear. If it is clogged or the inside diameter reduced, it would cause too much pressure in the pressure tank since it would not have the proper response time. The pressure would drop too low during use and then when the switch kicked in, the pressure would run too high before the switch itself would respond to shut off the pump. As cheap as they are, I suggest replacing the pressure switch. I suggest replacing the pressure relief valve also. The next step would be to drain and pressurize the tank. The pressure in the tank should be at least 2 psi lower than the cut in pressure of the pressure switch.

Now here's the part where you'll get varying degrees of suggestions and code quotes. I'll give my opinion and after the rest of the info comes in, you can make up your mind what you want to do. I'm suggesting you take a cup of pure (none soap containing or scented) bleach and take the cap off the well and pour the bleach down the well. Let it sit over night. If you have a deep well, you may not have an issue with bacteria but why take the chance. The next day, turn on the power to the pump and run your water through all the branch lines until you don't smell the bleach any more. It you plan to leave the well unused for several months to a year, i suggest you put 1 or 2 drops of iodine down the well. When you start up again, run the water as suggested when bleach was used.

Thank you, - yes the pipes are galvanized. I was going to take the whole thing apart and re-assemble it trying to use all brass if that is possible (the manifold section). The original plumbing was all done with CPVC (I think thatÂs what the white PVC supply line is?) but I would like to replace it all with PEX as long as there are no foreseeable issues with that. I donÂt plan on turning it on for another few weeks but I wanted to get as much advice I could before that time comes and I donÂt plan on changing the design of the components unless I find that it was done improperly (besides replacing items as suggested). Besides having the difference of 2psi between the cut-in and tank pressure, are there any general rules I should be aware of so that if something is wrong with the system now I can identify it and not repeat it when I re-plumb all of the fixtures?
If I understand it correctly, and as long as the pump is indeed in operating condition, a submersible pump needs no priming  is this correct?
And as for the bleach, pool chlorine (sodium hypochlorite) should suffice for this correct? (I think it is a little bit stronger that laundry grade)
The pressure relief valve should be about 20psi lower than the tankÂs listed safe operation pressure  correct?
I donÂt know for sure how deep the well is, but I am close to the top of a hill, would the amount of bleach differ if the well were 350Â as opposed to 125Â deep?
Besides installing the plumbing on a grade and installing a waste valve @ the lowest point to allow me to drain the system to prevent freezing when it is not being used, is there anything else I should consider? This is a hunting camp so I wonÂt be there during the week or very little in the winter aside from hunting season  it is in southern NY- . it looks like there is some heat tape on the black line that comes out of the ground from the well, should this be left on during the winter? Or can I do something like maybe open the check valve to allow the pipe to drain back into the well and leave the entire system dry? K

I believe you have given everything some thought and are on the right track.

Priming shouldn't be a problem. Anything you do beside taking off the check valve and letting the line drain, using the heat tape, etc. will give added assurance the line won't freeze to a point to cause any damage. When you take off the check valve, make sure the water does drain back to the pump. I have seen where systems have a foot valve in addition to the check valve near the tank. When I recommended a cup of bleach, I was assuming the well to be about 200 feet. If you are going to wait a week before coming back, that should be enough for any depth. Leaving the system dry is a good idea in freezing weather.

White plastic pipe is generally PVC and a white plastic with a yellowish tint would generally be CPVC. The pipe is labeled with stamping along the pipe. I know that where I am located, code requires the labeling to be viewable after installation. If that's not the case with yours, take an inspection mirror and look around the pipe, it's there.