The bathtub spout is leaking like mad and all the faucets are turned off

I believe it's a sterling

What do I need to do to fix this situation?

If you mean that water is coming out the tub spout, it's not the spout that is leaking, it's the tub valve. What kind of valve do you have, one handle or two knobs? How old (approx)?

As for the manufacturer I only seen the sterling name It has two knobs and as for an age I guess over 5 years since we bought the house in 2002 and we have changed nothing

Turn water off. Remove the handles or knobs. Remove the stem covers and escutcheons. Some stem covers slide off some unscrew. Remove the stem. For this you will probably need a set of tub sockets or wrenches. Tub sockets look like big ugly cheap socket wrenches. That's because that's what they are. The have a hole in each end that you stick a screwdriver through for a handle. Available at Home Depot and Lowe's. The firs nut you see around the stem will the bonnet or packing nut. It keeps the water from coming out around the stem. The second larger will be the shoulders of the stem. That's what you use to remove the stem from the body of the faucet.

If you have cartridge type washerless stems, replace. If the stems have a washer on the end replace the washer. You should also replace the seats at this time also. The seat is the removable surface in the faucet that the washer presses against to shut off the water. For that you will need a seat wrench, shown below. Remove the seat and take it with you to purchase new ones. There is a thousand an one different sizes, shapes and thread seats. When reinstalling stems install with the stem in the open position, otherwise the end of the stem may bottom out against the seat before you have completely screwed it back into the body of the faucet.

This may help aloong with the directions Harold gave you. This valve has a diverter but the general lay out is the same for a two handled valve. Don'tforget to check the seats for nicks and rough spots when you replace the washers. Good luck, Tom