Here's a site I came across today: Masterpiece Art Instruction. It's specifically aimed at homeschoolers, so I think you'll find it particularly useful. There's a monthly newsletter with lesson and project ideas, online classes, free download-able lesson plans and project templates, and also lessons and other products for sale.
Masterpiece Art Instruction is a very well designed site, simple and easily navigable. It's rare to find such a website that's not stuffed to the gills with banner ads or awkwardly designed. Simple and easy to use, with helpful information for your art teaching--it's definitely worth a look.
