About 25 years ago I read somewhere "The only way to learn to cast bullets, is to cast bullets". So, I did. But I agree with the posts above mentioning Lyman's Cast Bullet Handbook (I prefer the 3rd Edition for a beginner, but that's prolly hard to find and the 4th Edition is also excellent and has a bit more data on more bullets). You don't need to spend $$$ to get started and I began with a 2 qt. SS pan, a Coleman stove, a Lee ladle, and a Lee 44 cal mold. I fluxed with bees wax, paraffin, and sawdust, stirred with an old slotted spoon from Ma's kitchen and dip lubed with alox. Even though I had only a 50%-60% keepers at first, I just kept casting and a short time later the keeper percentages went up to about 90%. I shot a lot of cast bullets from that set up for about 10 months before I got a bottom pour pot. I now have 14 molds and about a half ton of ingots laying on the floor of my shop...
I have found a lot of very good info on all aspects of lead bullets from alloy, casting, lubes, loading, shooting, equipment, coatings, and methods here;
http://castboolits.gunloads.com/