This is the intro to the oringinal recording of Okie From Muskogee.  
It would start in E and modulate to F after the chorus.

e--0--0--0------0--0----------------0----------------------
b------------4---4------5----5--4-5--5-4---4---------------
g-1--2--3--4--4---4-4/6--6-6-------------6----4--2--1------
d---------------------------------------------6--4--2------
a----------------------------------------------------------
e----------------------------------------------------------

This is some of the fills they would use after it modulates to F.
You want to rake the chords.

(fill 1)           (fill 2)          (fill 3) 
e-5-6-8---------   e---------------  e---------8-10-12------
d-6------x8^pbr6   b-5-6-8---------  b-5-6-8---8------------
g-5-------------   g-5------x7pbr5-  g-5-------9------------
d---------------   d-5-------------  d-5-------10-----------
a---------------   a---------------  a----------------------
e---------------   e---------------  e----------------------

Forgive me if this isn't perfect, i'm doing this by memory. 
Merle starts this in D and kicks up to E now and that's the 
way we do it and there is no intro.
There is another fill they play now after the third one when 
they go back into F or E(whatever key you play it in).
Be sure and let all the notes ring.

e----------------------
b-5-6--6----------6----
g-------5-7p5-----5----
d-------------8p5-5h7--
a----------------------
e----------------------