How To Read A Chord Diagram
Here's how to read a chord chart. There are 6 vertical lines which represent the strings. The thickest and lowest sounding string is on the left, and the thinnest and highest sounding string is on the right. There are also horizontal lines which represent the frets. The top line is the nut (or capo if you are using one). The rest of the lines are frets 1 through 5.
Above the chord is usually written the chord name (A minor in this case - where the "m" means minor) If there is an "o" or circle above a string, that means play the string, but don't use any fingers on it. This is called playing a string "open." If there is an "x" above the string, that means do not play this string. There are 2 basic ways of doing that: you can either avoid the string with your picking hand, or you can mute the string with one of your hands. The dots are where you put your fingers. One note about reading these diagrams is that it's like looking at the neck of the guitar as if it were directly facing you - which is at first a little counter-intuitive.
Below the string is written which finger of your fretting hand (left hand for right-handed players). Sometimes a finger will play multiple strings, by laying across more than one, this is called a "barre" (pronounced like bar). If the x above a string is between two dots (fingered notes) then you will mute that string by leaning a fretting finger against the string to be muted. Another variation you may come across is where the finger numbers are either on top of the black dots, or replace the dots instead of being below the strings.
One last chord diagram I've come across is a way to represent a chord in simple text. The Am chord we've been using would be written like this- X02210. You read from left to right where the left number (or "x" or "0") is the 6th string Low-E and the right number is the 1st string high-E. Just like as before the "x" means don't play and the "0" means to play it open. This is a convenient way to write a chord when you can't draw it (like in an email). Downside is it's not very visual and doesn't have any fingerings with it.