There are several sites which are very helpful, one place that has compiled a great list of these resource is run by the publisher Houghton Mifflin Harcourt, called Education Place.
A resource for printer friendly worksheets is Jane Pimetel Printable Math, it does a lot more than just math, there are grammar and punctuation, math, science and many other worksheets for kids from K-12.
Janepimentel Printable Math
For those who are interested in a Christian education system which has had students accepted into many colleges and universities without problems there is one source that stands out for longevity and meeting a higher standard than unguided systems. A.C.E. Accelerated Christian Education has been in business for more than 40 years. This system uses work books that have a child working at their own pace, to develop a very good education. The course work covers a very broad range and is easily administered by a parent or small group of parents.
Accelerated Christian Education
Here is a partial list of the colleges and universities that have accepted ACE students: http://www.aceministries.com/aboutus...ollegeUniv.pdf
There are a ton of resources out there for parents who wish to home school their kids, one of the most important aspects of home schooling is the same one that is important when your children are going to public or private school on land. You have to be engaged in your child's education no matter where your children go to school. Teachers and administrators are not parents to your children, and good parenting is the key to producing good children.
I would encourage anyone who has school aged children on land or at sea to become more involved, and to take a full interest in the education of your children.