Here's how it works:
If your undergrad university has a pre-medical office, usually you go to them and they will open a file for you. What happens is every time you have a letter of rec (LOR) written for you, the person that writes it will send it to the pre-med office of your university and they will put it in your file. After you compiled all of your LOR's in the file, they will wait for you to tell them where to send the LOR's.
So let's say you have 3 LOR's sitting in your file. You decided to apply to 5 schools. You can now go to your pre-med office and ask them to send all of your LOR's to each of those 5 medical schools you applied to. When you actually have them sent is up to you. Some people say to have them sent before you send in the secondaries, some say after.
To make things easier on the person writing the LOR for you, give them a self addressed stamped envelope with the address of the pre-med office already on it, so they can just put the LOR in the envelope and mail it off without much hassle.
Now, if the undergrad university you attend does NOT have a pre-med office, then I think you'll have to ask the person writing the LOR to make multiple copies and send them to each medical school you're applying to. I might be wrong about this, though. My school had a pre-med office so I'm not sure how to go about it if your school doesn't have one.
To answer your other questions, usually one general LOR is written that goes out to all the medical schools you applied to. However, if the person writing the LOR wants to, they can write a different LOR for a specific school. For example I had a DO write an LOR for a specific school because that's where he graduated from. Then he wrote another general one for all the other schools I applied to.
Some schools will send you a recommendation form to be filled out by your recommenders. Usually, though, it can be replaced by an actual LOR. Sometimes they might want the form filled out and a separate LOR as well, but I don't know of any schools that do that. If the school sends you a form and you're not sure if it has to be filled out or can be replaced by an LOR, best bet is to call the school and ask. Get used to calling medical schools and finding out about the status of your file at their school.
To answer your final question, you're not supposed to see the LOR. Once it is written is it usually sent out by the person who wrote it either to your pre-med office (if you're school has one) or directly to the medical schools that you've applied to.
Hope that helps. Good luck in the application process!