I did the same thing about 15 years ago. Consider in the beginning, relying
on a commercial curriculum. When I started, there were few commercial
curriculua available and I wrote everything - and I do not recommend your
doing that! A commercial curriculum will give you the lessons to get
started with the entire program - and then as time permits, you can make
that curriculum better with your own lessons.
Consider calling Dale Seymour Publications at l-800-872-1100. Their K-8
curriculum is not perfect, but it is a good place to start. The name of the
program is Learning to Look and Create: the Spectra Program. Each grade
level has only one binder which contains all the lessons and the visual
resources in the form of slides. The production lessons usually employ art
supplies that the regular classroom teacher has access to. As I said
earlier, it is not perfect, but it is a place to begin and the program does
not require your school to purchase classroom sets of textbooks. Good luck!