What's a good source for h.s. math worksheets to supplement the textbooks? I'm aware of PH's site. Any other good ones? Thanks!
Try www.edhelper.com While it's a subscription site, he does have quite a few freebies. Disclaimer: I was on the edhelper payroll for 4 months as a freelance writer a few years ago. But I would recommend the site even if that weren't true.
Jefferson Math Project is an extremely good one; just google it. But it's intended for NYS math. My wife uses it a lot.
For Pre Algebra and Algebra.. my kids love the pizazz series.. turns the math problems into a riddle for them to solve.