Algebra
Ms. Lindquist The Free Algebra Tutor -- You'll love her.  Must visit!

Algebra
QuickMath Automatic Math Solutions -- An online equation solver that solvess all sorts of algebra and calculus problems - instantly and automatically!

Algebra Help
URL : http://www.algebrahelp.com/
AlgebraHelp features lessons to learn or refresh old skills, calculators that show you how to    solve problems step-by-step, and interactive worksheets to test your skills.

Algebra
URL: http://www.bbc.co.uk/education/asguru/generalstudies/maths/13algebra/index.shtml
This site uses diagrams, animations and interactive assignments to illustrate concepts in Algebra. Study skills in doing Algebra as well as general areas are given.    

Arithmetic
URL: http://www.bbc.co.uk/education/asguru/generalstudies/maths/10numberunits/index.shtml
This web site uses diagrams, animations and interactive activities to illustrate various concepts and study tips for pupils are also given.

Graphs
URL: http://www.bbc.co.uk/education/asguru/generalstudies/maths/12functionsgraphs/index.shtml
This site provides diagrams, animations and interactive assignments to illustrate various concepts and general study tips are also given.

Mensuration
URL: http://www.bbc.co.uk/education/asguru/generalstudies/maths/11shapespace/shapespace01.shtml
This site provides diagrams, animations and interactive assignments to illustrate various concepts and general study skills are also given.

Trigonometry
URL: http://www.bbc.co.uk/education/asguru/generalstudies/maths/11shapespace/shapespace08.shtml
This interactive site provides diagrams, animations and activities to illustrate certain concepts as well study skills in general are given.

Statistics
URL: http://www.bbc.co.uk/education/asguru/generalstudies/maths/14statisticsprobability/index.shtml
This site provides diagrams, animations and interactive assignments to illustrate the concepts and general study skills are also given.

Probability
URL: http://www.bbc.co.uk/education/asguru/generalstudies/maths/14statisticsprobability/index.shtml
This site provides diagrams, animations and interactive assignments to illustrate the concepts and general study skills are also given.

Math Net
URL: http://www.mathsnet.net/
This interactive site has a lot of resources such as puzzles, software, curriculum, recommended books and even a Math Net Trail.

Math Tutor
URL: http://www.mathstutor.com/Menu.html
This site has been developed with the purpose of assisting pupils in doing their revision in Mathematics. It covers a range of topics in Arithmetic, Geometry, Algebra, Statistics and Graphs, etc.

Mathematics Education
URL: http://www.math.fsu.edu/Virtual/Education.html
A web site that has more than 100 links to the various Mathematics websites ranging from primary to college levels.

Ministry of Education, Singapore (intranet!)
URL: http://intranet.moe.edu.sg/ier/listsect.asp?subject=Mathematics

History of Mathematicians 
Bibliographies of over 700 mathematicians. A list of references accompanies each biography or history topic. http://www-groups.dcs.st-and.ac.uk:80/~history/Indexes/Full_Alph.html

When all else fails        
Secondary Math Resources -- This is a page full of links to Math sites.

Games for the classroom use (plus other stuffs of course). 
http://www.teachnet.com