More suggestions added above.
Also, welcome to all newcomers to homeschooling. If you have any questions, please don't hesitate to ask. You will find the homeschoolers here very helpful.
Here are a few more links. Some of these sources were mentioned in posts above, too:
SUPPLIES:
The Key To Series: Fractions, Decimals, Percents
http://www.keypress.com/catalog/products/key_to/index.html
Also see "Key Curriculum Press" mathematics by clicking on "Home" there.
Educators Publishing Service
http://www.epsbooks.com/
"Explode the Code" (mentioned already here) is available there. We've used "Ridgewood Grammar".
ORGANIZATIONAL NEEDS:
Donna Young's Free Printables:
http://donnayoung.org/
The HomeSchool Mom
http://www.thehomeschoolmom.com/gettingorganized/allplanners.php
UNIT STUDIES: BASEBALL
My 9yo son loves baseball. Here are some free online lesson plans we found on baseball math, physics, sportswriting, etc.:
PBS Fantasy Baseball (this is a PDF file)
http://www.pbs.org/teachersource/mathline/lessonplans/pdf/msmp/fantasybaseball.pdf
The Batting Cage
http://library.thinkquest.org/11902/physics/batting.html
Fun with Baseball Stats:
http://www.teachersfirst.com/autoframe.htm?http://illuminations.nctm.org/index_d.aspx?id=257
Learning from Baseball
http://www.teachersfirst.com/baseball.htm
Physics in Sports connection (online video):
http://archive.ncsa.uiuc.edu/Cyberia/VideoTestbed/Projects/NewPhysics/newtons_3.html
Hope all is going well for all of you!