google.com is, I think, the most refined search engine online. I have never had any problems finding information when using it. http://www.google.com
www.math.com is an excellent tool for just about all your math needs. It gives many examples and walks you through many subject matters in any math course. I referred this to my past Algebra I classes, and they gave it a "Thumbs up," and I feel strongly about it with Geometry as well. http://www.math.com
yahooligans! math is a great site to find information on just about any topic in math. Don't understand how to measure angles? Just type in "angles" and use it as your own personal search engine to find your answer. http://www.yahooligans.com/School_Bell/Math/Real_World_Math/
Thinkquest's "Online Math Applications" is a great site to explore the uses of mathematics. Don't think you'll need math in the future? Think again. http://tqjunior.thinkquest.org/4116/
Here is a website that has some neat interactive visualizations with fraction operations. http://nlvm.usu.edu/en/nav/category_g_3_t_1.html
In particular, here is an area representation for multiplying fractions. http://nlvm.usu.edu/en/nav/frames_asid_194_g_3_t_1.html
Online interactive math facts in all of these areas: Addition and Subtraction of Integers Addition and Subtraction of Fractions Multiplication and Division of Integers Multiplication and Division of Fractions Percents Ratios http://www.aaamath.com
http://www.bbc.co.uk/education/mathsfile/gameswheel.html
Choose any of the 6-8 websites and activities. http://nlvm.usu.edu/en/nav/vlibrary.html
Equivalent fractions and other fun activities http://www.learningplanet.com/sam/ff/index.asp
Equivalent fractions and reducing fractions http://www.funbrain.com/fract/index.html
Fractions with pizza http://math.rice.edu/~lanius/fractions/index.html
Adding fractions http://fen.com/studentactivities/MathSplat/mathsplat.htm
Fractions, decimals, and percents applets http://www.bbc.co.uk/skillswise/numbers/fractiondecimalpercentage/
***** Nice website with different levels of Algebra. http://www.wtamu.edu/academic/anns/mps/math/mathlab/
Very good tutorials on Algebra I and Geometry. 5 Stars from me. http://regentsprep.org/Regents/Math/math-a.cfm
Great website. Check this out for some tutorials and other useful items. http://www.pasadenaisd.org/sailon/HS_geometry.htm