Well, that's a big subject!
Here is a place to read up on the gun.
http://www.gunblast.com/Ruger-50thSBH.htm
The instruction manual should be read.
The following forums are a big help too :
http://rugerforum.net/forums.php
http://www.rugerforum.com/phpBB/index.php
Anything you should know? Well it will kick like a mule with .44mag loads. Be prepared......
As far as ammo is concerned, you can shoot .44 Special or .44mag out of the revolver. As a reloader, I personally load my .44mag down to .44 Special loads as full house .44mag aren't much fun for extended shooting sessions.
I assume you have shot before? The .44mag isn't a beginners revolver. Shoot .44 Specials before moving up to .44Mag. With this revolver you can load all six as it has the safety bar.
Then, just go shoot it and get a feel for it. Takes a bit to get used to shooting a .44mag. Make sure you have a real firm grip the first time you shoot it. You don't want it digging a hole in the back of your hand or flying out of your hand. After a couple of rounds, you'll know better of how firm a grip you actually need. Wear ear protection and enjoy
! Oh, depending on your hand size and grip, it may rap your knuckle. If that happens you can tape up the knuckle before shooting. Some people don't get rapped. All hands are different.