Lock up the kids and the pets. My cat kept trying to run between my legs and that is just not a good idea. Use whatever essential oil you like to scent your soap. There are many available at natural health food stores. Let the soap cure for about a month before you use it.
Soap making is nothing more than a chemical reaction that occurs when the lye responds to the fat.
It's pretty cool to see this happening in front of you. The fat you use is your own choice. It can be lard or olive oil or crisco, etc. This is actually easy. Mix lye and water and set aside to cool.