The guitar tabs should be viewed (ideally) with a square font. This is a font where the letter W and the number 1 take up the same amount of space. The problem with the online stuff is that timing and spacing don't always translate well, which makes it difficult to tab songs people haven't heard. Here is how to read guitar tabs.

Read guitar and bass tabs

This is what a tab looks like (or at least how I write them): 
("Enter Sandman" intro)

e---------------------------
B---------------------------
G---------------------------
D--------5-------------5----
A-----7--------7----7-------
E--0-------6-5---0-------6-5
Each string is listed (although to save space, I sometimes cut out strings not used for a riff) The top string here ('e') is the smallest sring on the guitar with the highest note. The bottom string here ('E') is the largest string on the guitar with the lowest note. Both strings happen to be 'E' in regular tuning. So all the other strings fall into place and it looks somewhat like a guitar neck.
Now, the numbers. The number tells which string and what fret to play. 
  Ex 1   Ex 2   Ex 3  Ex 4          
e----   ----   -0-   -----------   
B----   -15-   -0-   -----------   
G----   -14-   -1-   ----------9   
D----   ----   -2-   ----5--9--9   
A--3-   ----   -2-   -5--5--7--7   
E----   ----   -0-   -3--3------  
Ex 1: This example shows "middle C" hold the A string (2nd from the top) at the third fret. Just pick the one string.
Ex 2: This example shows basically what example 1 did, but with 2 strings. So just play 2 strings. I have no idea why I put this here.
Ex 3: This example shows an Emajor chord. Hold the A and D strings at the second fret, the G at the first, and the other strings leave open.
Ex 4: This is an example of power chords. They can be played with either the three notes or just two, it doesn't matter much especially with lots of distortion.

How to read guitar tabs

Terms, Abbreviations, and other useless symbols

harm

harmonic; hold finger slightly above string and pick it can only be done at specific places on the neck (this takes practice and you should find someone to show you how, beause it's difficult to explain)

A.H.

artificial harmonic; more difficult than a harmonic, you have to mute the string with the thumb on the pick hand after you hit the note (this takes practice... blah blah blah, read above)

h

hammer on; (ie 7h8) fret and pick string at 7th fret, and without picking again "hammer" and hold string at 8th fret

p

pull off; (ie 9p7) fret and pick string at 9th and 7th frets, and without picking again pull finger off 9th fret and let 7th ring

/

slide up; note rises

\

slide down; guess

pm....

palm mute; holding the bottom part of your right hand (for right handed players) against the strings near the bridge keeping it from ringing. The dots that follow indicate notes (chords) above are also muted

full

^

bend note; this tells which note (the carrot) and how much the note should be bent (full means a full step higher, half is a half ect.)

~~~

tremolo; slightly bend and un-bend note to increase sustain

x

rake; mute strings with fretting hand by not quite fretting a note, but still holding strings. 


Retrieved from http://www.fretplay.com/how-to-read-tabs

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