For Fine Art Lessons: http://www.incredibleart.org
I recommend this one! On this site you can choose art lessons by grade, medium, artist, etc. Go to Art Lessons at the top of the page and begin your search.
These two sites are great for low key, fun crafting. Great for young students!
If your kids like TV shows, here are two educational and art based ones I recommend.
Draw me a story (On Amazon Prime) A “FINE ARTS” approach to reading and literature. Painters, artists, sketchers, and crafters use their unique talents to bring color and motion to a fascinating collection of familiar children’s stories from around the world. Good for all grades.
Creative Galaxy (On Amazon Prime) Follow the adventures of Arty and his sidekick Epiphany, as they search the galaxy to solve creative problems with art! Whether Arty needs to create a painting for the new children’s library, a stuffed animal for his sister, or make a mask for his jungle pretend play, Arty and Epiphany come to the rescue by enlisting the help of the most creative of all – the preschool home viewer. Good for Pre-K- 1st.
If you do not have Amazon Prime, you can also find some episodes of both shows on youtube.