M.N.
There is a video series that my hubby and I bought for our now 3 year old when she was about 18 months old. I found it at the library and liked it so much that we bought the whole series. It is called Preschool Prep. Their website is preschoolprepco.com. I call it the Meet The... series. They have Meet the shapes, Meet the numbers, ..colors, ..letters, and sight words. Each DVD is only 15 dollars. My oldest will be 3 this month and she knows her letters, numbers (1-10), colors and many of the sight words. With her watching the videos starting at 6 months, my 16 month old can count to 10, recognizes her letters, knows her shapes and many of her colors.
The videos are very entertaining and have a lot of re-watchablity. I highly recommend these videos to everyone. The earlier you start them watching the younger they learn.
You should be able to find one or two at your local library. That way you can check them out before buying them.
Best of luck with homeschooling. We plan to do the same with our kids. :o)
-M.