The Physics Classroom is a really great site if you want to learn high school physics. It provides clear, easy to understand explanations of the physics concepts taught in high school. There is more emphasis on concepts than on formulas, but sample problems do clearly show how to do the calculations to solve standard physics problems. A slight drawback is that the derivation of various formulas is not shown, but you can learn calculus and get a college physics textbook if you are interested in where those formulas come from. Overall, it is a great first physics course.
I took a look at a couple of lessons. You can tell that some thought has gone into them. It's a pity there aren't more problems with answers and their derivations described in detail. I can see someone using this site, coupled with a set of fun experiments and plenty of worked example problems, to learn about physics.
Oops, I linked to the tutorial only rather than the home page as I meant to. The correct link is http://www.physicsclassroom.com/. The review session has plenty of worked problems but you are encouraged to try them first. The Multimedia section has good animations and there are lots of suggested labs (See Teacher's Guide for these labs for a complete description).