HOW TO LOAD THE STAPLER PROPERLY.... I SEE THAT SOMETTHING HAS TO BE DONE WITH A PIECE OF METAL AT THE END OF THE SPRING....

on the end of the rod after the spring is on

There are two basic designs of staplers. The most common type is the Swingline or Stanley Bowstitch types. At the business end of the stapler there is a small catch that you need to pull rearward and the front staple head will drop down. Inside, you will see a metal bar and a spring. Pull the spring back towards the rear of the stapler and insert a full clip of staples appropriate for your stapler. Release the spring slowly so the metal tab pushes against the staples... should be pointed tips down. Put the stapler on a firm surface and press it as you would when stapling something. The two parts of the stapler head will join back together again.

Rexel Odyssey heavy duty stapler: The pring that pushes the staples into position can come losse if the stapler iss dropped. It's difficult to work out how to replace it! However, there are only two "lugs" that will take the circular ends of the spring. One obviously fits to the sliding staple retainer. The other to the back end of the pressed-metal inner body. However, to work, the spring must be threaded from this point along the pressed metal parallel-sided inner body back through a slot and over a rounded bent piece (shiny from prvious friction) and back down to the sliding staple retainer. It's trickey to do, but that's where it has to go in order to provide forward tension when the Stapler is closed.

"The staples load from the rear of the stapler. At the back end of the is a piece of black plastic that extends beyond the end of the stapler. This device holds the staples inside the stapler. To open the area where the staples are placed, push this extended button and lift up on it. The spring device that holds the staples inside the stapler will then slide out. Place a new strip of staples inside the stapler on top of the two metal guide rails. Then insert the spring device to lock the staples in place. The stapler is now loaded and ready to work. " hope this helps you out

Sue, First, confirm that you have the right size staples. They are sized in two dimensions - width and length. The most common width sizes are T50 and T35. Your stapler and your pack of staples should have a number such as this. Your stapler will accept staples only of the correct width but of various lengths. The lengths are given in fractional inches - 3/8 inch and 1/2 inch are common.
But perhaps your problem is how to open the stapler. It does not swing open like a stapler you would use for papers. Instead, it has a sort of spring piston that has to be removed from the back-end of the stapler. If you lay the stapler down flat on the table so that the hinge of the handle is at the upper left corner, then what I am calling the back-end of the stapler is the lower right corner. Pick up the stapler so that you are looked directly at this back-end. There is a small metal square at this corner that is spring-loaded and is held in place by a little hook. Push in on this metal square as you move it up (or is it down?) to disengage the hook. Now the piston will pull out easily. Put your staples in the hole (they will only go in one way) and replace the piston. I hope you found this helpful Good luck!

No official B&D diagram, but userLovenheim from http://www.fixya.com/ posted his/her own picture which I'm posting here:

The staples should load in through the end of the hammer stapler. The end is spring loaded to push the staples forward, so push the end - usually a crome square - into the handle end then move that part up approximately 1/4 inch and pull back. The spring mechanism should slide out so you can add new staples. These staplers take a specific size of staple and a certain number to allow you to put the spring mechanism back into the stapler. If you do not know the correct size for your stapler someone at your local hardware store can help you find the correct size and they will probably even show you how to load it. Good luck!

The person that asked this is probably long gone, but in case anyone else comes across this... I had the exact same problem when I dropped this same stapler today and the spring came out. After examining it for a bit, I realized where the spring had to go and fixed it.
Open the stapler the same way you would as if you were replacing the staples and look at the top piece, towards the back. There will be an elongated black hook here to attach one end of the spring. The trick is where you route the spring after that... look towards the front end of the same top piece, and you'll see 2 holes in the metal. You need to push the spring up through the first hole, then pull it back down through the second hole (you may want to use a straightened paper clip to snag the spring so you can pull it through that second one), and only then do you attach the other end of the spring to the hook in the sliding metal piece that advances the staples in the staple holder.
And that's it!

Hope the following is clear if not write back and I'll try to clarify, if you look at the body of the stabler molded to the body there is a bump that is round on the botton and kinda notched on top. the round part of the spring fits around the bump. The spring has a straight side and bent side. the straight side rests against the a flat bump which is slight back and lower than the round bump. the bent side clips into the notch on the handle (clip this end in last) I used a plier but there is very little tension involved the spring just returns the handle to the at rest position,