This is how I learned soap making and pretty much every new hobby I take on. www.youtube.com
There are a lot of great people that teach by doing. Watch enough videos of something you can get a good understanding.
I just bought one from walmart for $10 also. I was looking on ebay, garage sales and goodwill, but could not find anything at that price. No-brainer for small batches.
25% of Water to Oil. In this case if you have 100g of oil you would use 25g of water.
Here is how it works: Cross Multiplication
25%/100% = Xg/100g
No multiply 25x100 = 2500
Now multiple 100 times X = 100X
So 2500 = 100X
Divide both sides by 100 and you get 25 = X
Hope...