The first Smith and Wesson .357 was in 1935 and was called the Registered 357 Magnum. It came with a letter of registration and this is a highly prized gun now a days and commands a high dollar.
Model numbers came along in 1957.
.357 mag can be found in various models and sizes.
The small frame is called the J frame and is best for concealed carry an example is the model 60.
The medium frame is called the K frame and this is perhaps my favorite. It can be had with or without target sights, some models include: 13, 19, 65, 66. The stand outs are the M19 and M66 both are the same, one is blue and one is stainless, both have target sights.
The medium large frame is called the L frame and this is a great gun. The blue is 581 and 586, the stainless is 681 and 686. The 586-686 have target sights, this is also a great gun and will stand up to heavy magnum loads better than the K frame.
The large frame is called the N frame and the .357 where models, 27 and 28. These are also awesome guns.
There are other .357's I failed to mention but if you want to hunt or shoot a lot a 586-686 may be your best bet. Do not sell the K frame short, a 19 or 66 is really a great gun.
The .357 is a good gun to start with, I recommend that you shoot 38 specials in it until you are accomplished with the gun and then use .357 mags as you see fit. This will allow you to become a better shooter and save a few dollars as well.
It is always best to learn from an experienced gun guy. With a little effort you will find someone like me who would be happy to let you shoot different .357's and help you learn fundamentals.
Gun people are usually very friendly and helpful...I suggest Graybeardoutdoors.com as proof.