A really simple starter recipe is a basic pure olive oil soap.
32 ounces of olive oil
4.33 ounces of lye
10.10 ounces of water.
Makes 2lbs of soap.
And remember-alwaysalwaysalways add the lye to the water, NOT the water to the lye.
Edit: So that this is more a recipe and less a list of ingredients, lol-sorry
Wearing safety goggles and gloves, and in a well ventilated area or outside, add your lye to your water slowly in a stainless steel pot and mix gently with a stainless steel spoon. Mix until fully dissolved. You'll notice it gets hot-that's okay. Set it aside until it reaches about 120 degrees F.
While you're waiting for it to cool down, heat up your olive oil in a pot. You want that at the same temp as the lye water before you add them together. Once they're both around 120 degrees F, add the lye water to the olive oil and mix with either a spoon or a whisk or a stick blender or a paddle or something, depending on how big a batch you're making.
Stir stir stir. When it begins to trace, add any fragrances or whatever you want to it, but if you're doing a basic simple soap, stick with the base ingredients. Once it's at about a medium trace, pour the soap carefully into lined mold. Cover it-if the soap doesn't reach the top of the mold, stick a thing of freezer paper on top before covering the whole thing to prevent ash. Wrap the whole shebang in a towel and let it sit somewhere for 24 hours. Unwrap it after that and unmold, cut, and line up to cure (making sure the bars aren't touching each other). In a few weeks, you'll have a nice, mild olive oil soap.