For Math Dictionaries/Words Help:
http://www.coolmath.com/reference/online-math-dictionary.html
http://www.mathwords.com

http://www.amathsdictionaryforkids.com  (especially good for kids)

For Free Graph Paper (many types ... scroll down) Generator (in .pdf format):
http://incompetech.com/beta/plainGraphPaper

For Grades K-8 General Mathematical Assistance: http://www.arcademicskillbuilders.com/games.htm  (this one is fun !)

http://www.cited.org/index.aspx?page_id=86  (K-8 Screen-Based Tech w/ Math)

Here's one resource I found from the last link:  http://www.learningplanet.com/articles/mathmachine/index.asp#list  (you need to create an account w/ username and password, [it costs ~$40/yr ; and you can evaluate it for 10 days free] but this is great!) 

http://www.coolmath.com

http://www.321know.com

http://www.education-world.com/a_tech/sites/sites085.shtml
http://www.education-world.com/a_tech/sites/sites086.shtml

http://www.education-world.com/a_curr/math/index.shtml

For Grades 9-College General Mathematical Assistance: http://mathworld.wolfram.com

For Virtual Manipulatives: http://nlvm.usu.edu/en/nav/vlibrary.html

For Factor Tree help: http://nlvm.usu.edu/en/nav/frames_asid_202_g_3_t_1.html

For Penrose Tilings: http://www.geocities.com/SiliconValley/Pines/1684/Penrose.html (scroll down)

For Golden Pentagons/Pentagrams, see:
http://www.matheverest.com/NestedRegularPentagons-Pentagrams.pdf