I've been curing olives for quite a few years and have run the range of lye cures, salt box cures and various brines. After a number of variations I find that I'm happiest just using salt and patience. It doesn't get more simple than this but it does take some effort in the beginning and a lot of patience as they cure.
By not using more complicated cures I can wait to decide what to flavor them with and marinate them with herbs, oil and other things like garlic or peppers in small batches to suit whatever mood I'm in at the time. Though most often we simply eat them as they are from the basic brine.
If you don't live near an olive area you can order raw olives online. They range broadly in price.
I arrange ahead with an oil producer who is kind enough to sell me olives from his orchard. I get them for about $2 a pound. In past years even curing 4-6 pounds has left us buying olives by the end of the year. This year I'm putting up about 8 or 10 pounds.
I try to plan ahead as best I can and understand that the olives I put up today will be the ones we are eating the following year. Once you get in the habit it's pretty simple and makes for a nice seasonal family tradition.
Step 1: What you'll need
Salt! Any non-iodized salt will do. I don't know that you couldn't use iodized salt but every person and recipe I have seen or talked to has warned against it. Easy enough to just get non-iodized. I like kosher salt. The important thing is that it dissolves well in water. So, something like a corse sea salt will be fine but take more time. It's up to you.
Jars. Any glass jar you can seal will work. I used wide mouth jars in the past but eventually found I prefer glass milk bottles. The narrower neck makes it easier to keep any floating olives in the brine and we have a steady supply of them as we buy milk in glass bottles. You can use canning jars, apothecary jars or big decanters with bales on them. Whatever works for you. In my case I find a two pound bag of olives fits well in a 64oz/1.87 liter bottle.
A way to heat the water
An uncooked egg
A small sharp knife
A large bowl