The link Tunesmith has given is to something from atrick Costello. My link is something done by his dad, Pat Costello.
The pair have been responsible for a number of different bits of free web based tuition. They did a series of audio podcasts called The Daily Frail, where each lesson took a simple concept, for instance using a chord, or a picking pattern, then later the different concepts were built into real tunes or accompaniments.
I used to have them bookmarked, but they seem to have moved somewhere else. They do seem to be in the Internet Archive. Try this link BLICKY .
Quack!
GtD.