G-31, I also agree that you should do a ton of reading before you actually start reloading. In regard to 357Sig, I recommend that you wait until you get more experience loading regular straight walled pistol cases (like 40S&W) and regular bottle necked rifle cases (like 223Rem, 308Win, etc.). Bottle necked pistol cases are typically more difficult to load than either of the above. I load 7.62x25 and 30Luger. They're just more of a challenge, but OK once you know what you're doing.
The Lee Factory Crimp Die for straight walled pistol cartridges:
Your substitute for doing it right to begin with.