HI B.,
There are many many resources for all of that. My oldest is 18 and just graduated from high school. We have homeschooled since the beginning and she already has her advisor at the University where she intends on getting her doctorate. They are willing to walk her through her bachelor's degree to make sure she slides right into their program with no trouble. Not many kids are even thinking about a doctorate, much less counseling with an advisor at this age.
There are many accredited programs. Some are national accreditation and some are state wide. Check with your school system or online as to what is required in your state and then search from there. I have used several programs and done a lot on my own. Tests are sometimes provided by the program you choose but you can also take advantage of the public school testing seeing as you are paying taxes for that. Anything you want you can get online....
One piece of advise that has served my family well is that we didn't always stay on subject for grade level. For example, we would take an American History class instead of Ancient History because that's where my girl's interests were. We would lead into the other one but chronology, and the outline of what is to be learned when, is also a product of the public system. We made sure they got all their subjects but it is so much easier to teach to a child that is eager for information.
Good luck in your endeavors. It is not hard if you want your children to learn. Who better than you to lead your own child? I believe that is why God gave them to YOU!
God bless,
M.