I have a non-mathematician friend who is interested in re-learning algebra. I am more than happy to help, but I am in no position to judge what is a good introductory text --- only to identify when a text is a very bad one.
My friend is interested in starting from "basics" --- he's comfortable with order-of-operations, minus-times-minus-is-plus, and positive integer exponents. He's shaky with negative exponents, logarithms, and roots.
Any recommendations for good, freely-available resources?