When scrap lead runs about $1/pound and 9mm cast bullets can be had for $85 per thousand, it's marginal savings casting for pistol, and none at all if you factor in your time. Don't let that deter you, though. Casting for rifle is a fantastic savings, however, or else lets you shoot more for the same money.
Buy the Lyman cast bullet handbook. Get an inexpensive Lee bottom pour pot, figure out which molds you'd like to try and order them. Decide how you want to deal with sizing and lubrication - I've always used a lube sizer, but it's cheaper to get into the Lee tumble lube system and push through dies (I've never used them).
You need stuff like safety gear - denim jacket/pants, face shield, gauntlets - because everyone gets splashed sooner or later (and introducing dampness into the pot can cause an even more nasty steam explosion - ALWAYS be certain that anything you go to put in the pot is bone dry).
You will also need some sort of method for smelting your raw lead scrap into ingots for your production pot. You don't want to feed your production pot with scrap metal. I use an old cast aluminum pot and a coleman stove and do 20-30 pounds at a time (of the stove might collapse).
Misc items like a dipper or ladle, some beeswax or paraffin for flux..
BTW If you want to try blending some alloy and need a source of tin, the cheapest I've found is buying spools of 50/50 or tin/antimony wire solder at Wosely plumbing in Winnipeg.
Sorry for the disjointed post. I tend to jump around. start with a good book, though.