I have found that place value worksheets are readily available online. A few sites that I found for you are math-aids.com, superteacherworksheets.com and softschools.com.
Helpingwithmath has a great site that provides you with free worksheets that you can print to help your child with learning the concept of place value. They are easy to understand too.
www.schoolsparks.com/kindergarten-worksheets is a good place to find worksheets. There are some free worksheets available to download and there is also a workbook of worksheets available for purchase.
The internet :D
The website www.kidslearningstation.com/phonics/ looks to be the best place to find sereral different kinds of worksheets. These worksheets include but are not limited to antonym worksheets.
Here's the best place I could find for Dr. Seuss worksheets: http://havefunteaching.com/worksheets/theme-worksheets/dr-seuss-worksheets/. This website has worksheets and other fun activities that pertain to the books as well: http://www.seussville.com/Educators/educatorReadAcrossAmerica.php.
There are plenty of place value practice worksheets online. Maybe try these websites: www.superteacherworksheets.com/place-value.html and mathwecan.com/place-value-charts.html
WorksheetPlace.com is a great place for home-schoolers to find worksheets for their kids and students. Just go there, find the worksheets on the subjects you need, and print! Viola! Good luck and happy home-schooling!
You can find a lot of social studies worksheets for your students at socialstudiesworksheets dot com. That site is the best to find what you need for your students.
You can find music worksheets at Canadian international school
First go to http://www.ereadingworksheets.com/free-reading-worksheets/reading-comprehension-worksheets/inferences-worksheets/. There you should find multiple links as to what you are looking for.
The best place to get kindergarten addition worksheets to help the students better understand the math questions is at math addition dot com. Good source of worksheets.
Your son can learn fractions using the fractions worksheets printed off the fracmytions website. They have tutorial on how to fill them out and print also.