If you're making melt and pour soap, no, definitely don't add lye to it. If you're going to be making cold process or hot process soap, a lye solution is what you add to your fats/oils to create soap. It's a process called saponification, and there's a high-tech description of the process here:
I'd do a lot of reading here, go through a bunch of the recipe and technique posts on this forum, plus Google soap making sites and read through all of the tutorials, tips, and tricks you can find, then go from there. Some of the sites give conflicting information, and I think a lot of that is just because it's outdated info, but it never hurts to read as much as you can find, then come back here and ask any questions you have.
First I would suggest for you to get a book something like the "Soapmakers Companion" and read it from cover to cover to understand the basics, the millers website is excellent starting point as well. Forums have got a lot of info but you still have to know a the very basics
Etelka
