When someone asks me how to learn to play mandolin, the first advice I give is, "Go get one." When they start asking you, too, you'll be awed by how many haven't figured this one out by themselves.
If you can't afford to buy an instrument, borrow one. My fiddle and banjo are both loaned out to friends.
You'll need a way to talk about the strings and notes, too.
The strings have names and numbers: E, A, D, G or 1, 2, 3, 4. The first string is the highest-pitched, and furthest from your face. The neck is in your left hand, the pick's in your right. If you play upside-down and backwards, like Libba Cotton, Dave Parman, or Bill Spence, you're stuck with how the rest of us talk.
Frets are numbered, starting with 1. If I say "put your finger on the first fret" I really mean "in the space on the far side of it," where "far" means "farther from the body, closer to the peghead." Don't be so pedantic.
Fingers have names: index, middle, ring, and pinky. You'll see numbers, too -- 1,2,3,4 -- but it's easier to follow "ring finger, A string, fifth fret" than "first finger, second string, fifth fret."
I won't be teaching you how to read music. Nor tablature -- tab for short.
Reading music, like reading English, is a skill to take pride in.
To play our music, you don't much need it. This is music from the hills, passed on from one person to the next. The folks who made up these tunes and the ones who've played them for centuries were, in plenty of cases, as unable to read English as to read music. If they could do it, you can, too.
You will want to know the names of notes of the scale -- a, b, c, d, e, f, and g -- and basic ideas like sharp and flat (# and b), time signatures, beats, measures, .... You can pick this up by skimming through books or on-line tutorials, or by asking friends to explain it to you.
Lots of music is learned through watching and hearing, so you'll need that. I supply no video or recordings, and you'll have to hunt those up on your own. YouTube, MP3s, CDs, ... whatever's handy and works for you.
Better still, make friends with other musicians. Me, for example -- just come ask me to show you stuff.
If you're reading this to "learn to" instead of to "learn about," you'll also need doing. I supply no doing, either. I am doing for me, but that won't help you a whit.
If this seems like a lot, don't worry. You'll pick it up as you go, bit-by-bit, and by-and-bye. The rest of us did. We're no smarter or more talented than you are. Honest.
Every musician you play with who's better than you are has been where you are now -- whoever he is, wherever you may be. He went through this stage, too, and remembers. And got from there to where he is.
I use "he," because it is the generic, marker-neutral, third-person-singular, nominative pronoun used for people in English. The usage mirrors that of other Indo-European languages. You went through politically-correct schools or corporate, diversity-training seminars, which taught you to use "(s)he," "them," or "zher," and you now feel compelled to feign shock or indignation over others' use of conventional, grammatically-correct English? Bummer, dude. On reading it, you're dumb enough to infer that all musicians are men? A surprise awaits you.Now come play some tunes.
