The most important thing to know with tabs are that their actually upside down.
E|-------------------------------------------------------=bottom(smallest) string
B|------------------------------------------------------
G|------------------------------------------------------
D|-------------0-2-------------------------------------
A|--2--2---2-2-----2--2---2-2--0-1------------------
E|--------------------------------------------------------=top(biggest)string
The number tells you what fret
The lines show you what strings
when you have numbers directly over each other, it generally represents a full chord. It also means that you pick all of those strings at the same time. This is a full G
E|--------3---------------------------------------------------------=bottom string
B|--------0----------------------------------------------------------
G|--------0----------------------------------------------------------
D|--------0----------------------------------------------------------
A|--------2----------------------------------------------------------
E|--------3---------------------------------------------------------=top string
This is a full A
E|------0----------------------------------------------------------=bottom string
B|------2-----------------------------------------------------------
G|------2-----------------------------------------------------------
D|------2----------------------------------------------------------
A|------0----------------------------------------------------------
E|-----------------------------------------------------------------=top string
If a string has a 0 it means you play that string open, if it has no number it means you dont use that string in that chord it particular riff.
To play a F as a bar chord, you would use your index finger to "bar" down all the strings on the 1st fret at the same time.(see pic) Use your ring and pinky fingers to hold the 2nd and 3rd string from the top in the 3rd fret. Use your middle finger to hold down the 4th string in the 2nd fret. If you can manage that, you've made a bar chord.
E|------1-----------------------------------------------------------=bottom string
B|------1------------------------------------------------------------
G|------2------------------------------------------------------------
D|------3-----------------------------------------------------------
A|------3----------------------------------------------------------
E|------1-----------------------------------------------------------=top string
I hope some of that might actually help and not confuse you
Heres more stuff that might help
http://www.harmony-central.com/Guitar/tab-notation.txt