Well, I don't really have any websites.. but I will give you a little information, if you don't know
A fret is the individual blocks on a guitar, you know, the things with the small lines going perpendicular to the strings. Frets closer to the end of the guitar produce a more low pitched noise, while frets lowers on the guitar produce a higher pitch noise. When reading tabs, usually they mark out what fret, and on what string you should strum.
Example:
E|----------------------------------------|
B|----------------------------------------|
G|----------------------------------------|
D|-0-------------1------------3-----------|
A|----------------------------------------|
E|----------------------------------------|
All these tabs are on the D string, which is the 4th string. The 0 indicates that you are not pressing any string down, but you will strum that string only. The 1 indicates that you will hold this string down in the 4th fret. The 3, means you will hold this string down on the 3rd fret. Whenever a number is represented, you should strum that string while pressing the string down firmly in the fret shown.
Sorry if I missed or inacurately said anything.. I'm still learning too