Mathplanet.com was created in spring 2011 to spread mathematical knowledge worldwide. Everything on the site is free to use for non-profit purposes and you don't need to register in order to watch videos or read examples.
Recommended for PreAlgebra through Algebra 2 and Geometry.
Paul's Online Math Notes: Cheat Sheets and Tables An excellent, well-organized site by teacher Paul Dawkins. Covers very basic to advanced math topics.
Learning and Studying Techniques: Math Study tips with sample problems and solutions.
S.O.S. Math--This site contains tutorials covering algebra, geometry, trigonometry, calculus, differential equations, matrices, and complex variables.
Statistics How-To: Elementary Statistics for the rest of us! Site owned by a former math professor.
Colleges and Universities
LSC-O Learning Center Math Helps--This site, hosted by Lamar State College-Orange's own Learning Center, offers students a variety of math helps, videos and links. This is an excellent site for the college-prep math student.
Beginning Algebra--This site, hosted by West Texas A&M University, offers students step-by-step instructions. This is an excellent site for the college-prep math student.
Patrick JMT (Just Math Tutorials)--"Patrick", a college/university math instructor, presents videos on a vast range of math topics.
Math Learning Center at Del Mar College--This site features Factoring Videos, Math Handouts, COMPASS Prep Practice, and Assessment Reviews for Elementary Algebra, Intermediate Algebra, and College Algebra.
Practice math at your own pace with Khan Academy's exercises. You can start at 1+1 and work your way into calculus or jump right into whatever topic needs some brushing up.
Each problem is randomly generated, so you never run out of practice material. If you need a hint, every single problem can be broken down, step-by-step, with one click.
The iOS app lets you download videos to your device and watch them offline at your own pace. It also lets you track your progress to get credit for watching videos, and see your achievements.