You are asking one question that has a thousand answers and all are different.
Best thing if you are serious is to buy PO Ackleys Handbook for Shooters and Reloaders Vol 1 and 2. Should be able to get them from www.sinclairintl.com
He covers most of the improved cartridges, gives what works and does not, reloading data for powders existing at that time.
Beware you will find about 10 versions of every AI cartridge and most dimensionally different. That means unless you know which reamer print your die mftr is using, off the shelf or standard factory AI dies will often not work. That means talking to the reamer mftrs (Dave Kiff at Pacific Tool and Gauge, Dave Manson at Manson Reamers, Clymer reamers, Henrickson Reamers etc) and find out which die mftr is using a specific AI reamer.
You can go to any reamer mftr ( I use Dave Kiff at PTG) and get them to make a reamer for you (about $200 with go and no go guages) and then use Neil Jones to make a custom die set for any cartridge off the reamer print for $275-$300.