Invest in a copy of the Lyman Cast Bullet Handbook and read it. There are some safety considerations to be aware of, like no water (or sweat) near the pot, ventilation, etc.
I used the $60 Lee bottom pour pot and Lee molds for a long time. Just recently upgraded to an RCBS furnace and love it. Midway has it on sale and RCBS is running a rebate but it's still a lot more expensive than the Lee.
Don't put scrap lead in your casting pot without cleaning it up first. Even highly pure scrap will have some crud on it. Melt it separately, flux it with sawdust or paraffin, and pour it into muffin pan ingots for future use. Goes double for wheel weights.
I'm lucky that the bullets drop from the mold without the need for sizing in my guns. For smokeless powder cartridges I use Lee Alox and tumble them. It is easy to overuse Alox...I dilute it with mineral spirits and use just enough to get a slight dulling of the bullet surface. Just knock the shine off. If the bullet is really sticky, you are using too much and it will foul up your loading dies.
For blackpowder cartridges, I dip the bullets in a beeswax/Crisco mix, deep enough to cover the lube groove, again without sizing. It works for me.
When casting balls or bullets, I like to run hot and fast. I open the sprue cutter as soon as the surface is frozen and thumb pressure is sufficient. I do not like to pound on my molds with a mallet, and running fast makes it unnecessary. Keep the molds clean and the balls/bullets will shake out easily. Don't be afraid to let a lot of excess molten lead run out on the sprue cutter while filling the molds. You want to keep the sprue cutter hot, otherwise it will chill the molten lead as it enters the cavity, making wrinkly bullets. Avoid putting anything other than a wisp of smoke from a lit match in the mold cavity. I used the aerosol graphite lube the first time I tried casting...a messy mistake.
Harbor Freight has welder's gauntlets for about $10; a good investment.