I have a friend who want to learn to play the guitar. Basic chords and stuff. Any suggestions on a great free or low cost online program?
Great, maybe.
Low cost, well that is relative to the value you place on the info.
On-line, yes both of these.
But remember I am biased as I amm invested in both these two sites. I am not musicstudent for no reason)
David Walliman
https://www.guitarplayback.com/courses/David's website and entire business is dedicated to Guitar lessons. I have worked with him on and off over the past 10 years. He has sales frequently for his program offerings and gives a lot of very informative lessons and teaching free on a regular basis.
Ayla Tesler-Mabe at
www.guitario.com is also on my for list for lessons. But actually I am a lifetime member of
www.pianote.com which is their sister on-line lesson program. I have studied with Lisa as a beginner for the past year and a half on piano keys. Excellent lesson plan for reasonable cost (again look for sales). Only recently did they start up guitario.com for guitars. Ayla is a guitar prodigy. They do the guitar lessons very similar to the piano courses, so I don't think you could go wrong for structured on-line lessons.
Both these sites have a huge web presense with lots of free demos to entice a new student. So try both out. if one of the instructors fit your style then it is time to invest. Structure is what you want as a new player.