Wow, Cathy, once again good info on your website. You're so methodical and meticulous that I think you and I both think very similarly. I'm glad I don't have any particular interest in doing a soap site. I'll just use yours!
ilovedoxies, just keep asking for any part you don't understand. You'll find that forum people are always willing to help beginners, particularly at SMF. I'm sure we'll get you squared away if you just keep asking.
Honestly, SoapCalc looks very complicated at first. I remember looking at it the first time and saying, "What the heck???" But it's deceptively complicated appearing, and much easier to use than it looks like. In fact I'll try to add just a bit to what Cathy said above.
The primary purpose of SoapCalc is to tell you how much water and how much lye to use. You pick the oil or oils and SoapCalc does the rest. In the beginning you should use SoapCalc to figure out recipes you already have, perhaps ones from books, forums or the Internet. Start out with SIMPLE recipes, certainly none with more than 4 oils, and at first just do a few single oil recipes.
One more thing before we start. There is SoapCalc and SoapCalc WP. The WP version can be reached by clicking the WP link at the top of the SoapCalc page, and WP stands for "weight and percents." The regular calculator works for percentages only. Often you will find recipes with weights listed but no percentages. You can manually calculate them but it's easier to just use the WP version. So if you are checking out a recipe you have weights for use the WP version which is practically identical except for the weights.
Important: once you have a recipe going you can then scale them to any batch size you want! This is the other primary purpose of a calculator besides telling you how much lye and water to use!
You scroll that list of oils in the middle until you find an oil of interest, let's say olive oil. Highlight olive and then over to the right click the plus + sign to add an oil to your recipe. Let's make a one oil soap. To the right of the olive you just added in the percent column put 100 for 100 percent. Now click "Calculate" and your recipe will appear below.
Note the "total oil weight" box in the top just left of center. That allows you to change your batch size. Enter a different weight and hit calculate again and see how the recipe is recalculated with the new weights.
There's only two more important things I have to cover, the other two settings that many of us change. They are lye concentration and superfatting. The defaults are a superfatting of 5 percent and a lye concentration of 25.3 percent. You don't need to change it in the beginning and the default settings will work fine. I still use 5 percent superfat except on rare occasions. However, I've always used 30 percent lye concentration because I think the lesser amount of water helps the soap set up quicker.
Well I hope two (or more) explanations in different words will help. Also, Cathy and I have covered different parts to some degree, so perhaps after reading both and playing with the calculator a bit maybe you'll have a better understanding. Feel free to ask for more explanation of any parts that are giving you trouble.