This question came to me from an adult client. My reply follows it:
Q: Do you think it’s beneficial for guitarists to learn to read standard notation and, if so, what method do you recommend for doing so?
A: I think music, because it is a language I learned when I was in second and third grade and have used all of my life. That said: Sure, learn to read music and learn to understand how music “theory” works, even at an advancing age! It provides a way of thinking that tab-only guitarists generally don’t possess. But, be aware that learning a new language when you are an adult is quite an undertaking. But it will be good for your brain cells!
Take an introductory music class at a local junior college. They’ll make you play the piano (not necessarily well!) because music is so easy to visualize on a keyboard. More advantages to that approach: there will be some outside “pressure” to actually do the work, plus there will be someone to answer your questions!
If you find that learning a new language is too hard for you at this point, rest assured that there are great musicians who never learned to read music: Paul McCartney to name one. He’s been pretty successful…
But above all, I think that learning music is about listening. Wasn’t that the traditional way of learning music long before the advent of papyrus and writing utensils? Isn’t it still the way we learn to love music, sitting at your elders’ knee? To that point, we just saw the recent Linda Ronstatd movie. (We recommend it!) She recalled as a child falling asleep in a family member’s lap as her father played guitar and sang Mexican folk songs.
My admonition to you: Yes, learn to read music, which will likely be a slow process. But, before you undertake that, sit with a fingersyle guitar recording and try to figure it out JUST BY LISTENING! Don’t go to YouTube. Don’t look for the tablature online. Use your ears. Can you hear a C-chord shape? An E-minor chord shape? Can you detect alternating bass? Can you hear an alternate tuning? (Hint: Listen for chordal harmonics.) Listening and imitating is how you grow as a musician.
Try figuring out some early Bert Jansch or Dave van Ronk tunes from their recordings. I suggest Jansch’s “Running From Home” and van Ronk’s “Cocaine Blues.” If you find them on YouTube, just listen. Don’t watch! I’ll give you a hint: Bert’s tune uses a capo and G and Fmaj7 chord shapes (fret the sixth string with your thumb), and Dave’s classic version uses key-of-C shapes, plus he slides up to an E7 chord at the 6th and 7th frets (a B7 shape, if you will).
Good luck. Pat yourself on the back when you figure them out. THEN go look at the tablature.