Last December I had asked for and received an instructional DVD called No Nonsense Jazz Guitar by Jimmy Bruno. It starts out simple, and Jimmy does employ a no-nonsense approach, but the DVD quickly moves to harder material, without any preparation. One minute, you're learning a simple scale pattern, but then the next minute you're learning about doing changes over a 2-5-1 progression.
To fill in my knowledge, I went out to the Internet and found lots of tutorials. There are many tremendous jazz instructors (I like Jens Larsen and Matt Warnock) who take a far slower approach at the material. These side investigations into concepts that Jimmy introduces ("passing notes", "modes", "triads", "Circle of Fifths") have introduced me to music theory, a body of knowledge that is quite rigorous and analytical.
In the end, what's really helped is learning how to play jazz songs, the whole point of my wanting to learn jazz guitar. But unlike rock or R&B, jazz songs are fairly complex, and use very different chord forms. I learned songs like "I Can't Get No Satisfaction" (Rolling Stones) or "Big Me" (Foo Fighters) in an afternoon, but I've been working on the jazz standard "Autumn Leaves" for the past two months. (My excuse: I only practice 30-45 minutes a day.)
I'm not deterred though. I'm okay with my pace, because learning this genre of music has been challenging yet engrossing, and I expect I'll be pursuing this for a while.