Randy Hunter's lessons are just $6.99 each and a nice affordable way to begin to explore the vast world of online lessons. A while back Randy was nice enough to send me several of his etude books (with CDs). There have been a lot of these types of book/CDs coming out and many are very good. These are a good way for students to learn Jazz phrasing and to practice sight-reading. Play-along etudes are an entertaining way to practice as well.
Randy's Jazz etude & duet books are available for tenor sax, alto sax, trumpet, trombone, flute. He also has Jazz combo books for wind & rhythm section instruments. I used his etude books with my students and they seemed to really enjoy them, especially the beginners.