HTML> Math Literature Ask Dr. Math - This is by far the best general resource on math for high-school students that I have found. Questions and answers for high-school level math questions are located at this site. You can also ask Dr. Math your own question. If you cant find your answer there, check out the College-level questions and answers.

WebMath: The Internet site that solves your math problems This site has many sample math problems and solutions for high school level math. The types of problems covered fall into these categories: everyday math, numbers, fractions, graphing, simplifying expressions, polynomials, factoring polynomials, quadratic equations, word problems, and even a little physics.

DAU Math Refresher A great site with Algebra and elementary Calculus help. This site also has online tests you can take after completing the math tutorials.

GCSE Mathematics Tutorials This page inclues short, but useful tutorials on negative numbers, probability, and basic trigonometry. The tutorials are well explained and laid out usin Java. This site also has math questions on algebra, functions, graphs, probability, and trigonometry.

Daves Math Tables This is not a tutorial, but its a great way to look up math identities and such. Math subjects covered include general math, algebra, geometry, trig, statistics, and calculus.

Algebra

Algebra Like an advanced algebra textbook online, unfortunately there are no sample problems. Topics covered include: real numbers, notation, polynomials, inequalities, factoring, quadratic equations, graphing, conic sections, polynomial functions, exponential and logarithmic functions, linear algebra, and discrete algebra.
Interactive Algebra Tons of sample algebra questions with step by step solutions. Web users can try to anwer the questions and then see the solutions. There are three units on this site, equations, factoring, and graphing.
Online AlgebraAn algebra textbook online. Nothing fancy and no problems to try on your own, but still a good site for basic information.
S.O.S. Mathematics - Algebra Another Algebra textbook online. This site does have a few practice problems in each unit. The units covered are: fractions, units of conversion, complex numbers, quadratic equations, factorization, solving equations, inequalities, inverse functions, logarithms, and rational functions. Lots of advanced algebra information.

Geometry

Interactive Math Online: Geometry Comprehensive and understandable geometry information in a textbook-like format. Lots of sample problems with solutions.
Geometry problems, theorems, and proofs Get some practice with these interactive geometry problems. This web site also has a list of theorems and proofs as well as a timeline of geometry. In English and Spanish
Geometry >Like a geometry textbook online, unfortunately there are no sample problems. Topics covered include: segments and rays, angles, parallel lines, triangles, polygons, tangent, arcs, chords, and circles, and on and on.

Trigonometry

A Short course in trigonometry A great site with useful and understandable information about trigonometry. Each section has java applets that explain trig. concepts as well as a few sample problems with solutions. Sine, cosine, tangent is explained as well as chords, tangents and slope, and trig. identities.

Calculus

Interactive Resources for Calculus I Get some practice in with these Calculus problems covering all sorts of topics. Hints, answers, and details are provided for each sample problem.
Karls Calculus Tutor Karl is a friend to the 1st year calculus student and this web site proves it. Comprehensive coverage of first year calculus concepts with pictures and graphs. No sample problems though, too bad.
Calculus Graphics - Pictures and explanations of many basic calculus principles.
Calculus Lessons - Explanations of some specific calculus principles, none of which I recognize, so this site may have limited usefulness to high school students.

Other Math Stuff

Fractals and Scale: a Fractals Tutorial - An interesting, basic tutorial on Fractals.

Math History

MacTutor History of Mathematics Archive Includes a massive index of mathematician biographies as well as an index of important math discoveries.
Ancient Math - This site is more history than it is math, but it is interesting.
History of Algebra and Computing - Another history of math site. Not too much information on doing math though.
History of Math - Still more math history with over 1000 biographies of mathematicians.
3 stars Women Mathematician Biographies - Lots and lots of biographies.