This is the main theme song for the Harry Potter movies... 
I figured it out pretty quickly so it's not very hard at all. 
It's a hell of a long song though, so be prepared.

If you get confused on the tempo just check out this youtube link:
http://www.youtube.com/watch?v=-vq-TmvL4CA&feature=related

Tuning: Standard (EADGBE)
Tabbed by: mEgAn

Overall order of the song 
(based on the #'s I put next to the tabs):
1 2 3 4 5
1 2 3 4 5
1 2 3
6 7
6 7
6 7
8 9 10
6 7
8 9
11 11
6 7
1 2 3

HEDWIG'S THEME
1) e|---0-3-2-0-7-5-2-|
   B|-0---------------|
   G|-----------------|
   D|-----------------|
   A|-----------------|
   E|-----------------|

2) e|-0-3-2---2---|
   B|-------3---0-|
   G|-------------|
   D|-------------|
   A|-------------|
   E|-------------|

3) e|---0-3-2-0-7-10-9-8-5-8-7-6-----0-|
   B|-0--------------------------7-8---|
   G|----------------------------------|
   D|----------------------------------|
   A|----------------------------------|
   E|----------------------------------|

4) e|---7---7---8-7-6-----7-6-2---7-|
   B|-8---8---8-------7-8-------3---|
   G|-------------------------------|
   D|-------------------------------|
   A|-------------------------------|
   E|-------------------------------|

5) e|---7---7---10-9-8-5-8-7-6-----0-|
   B|-8---8---8----------------7-8---|
   G|--------------------------------|
   D|--------------------------------|
   A|--------------------------------|
   E|--------------------------------|

Play #'s 1 through 5 twice. Then play #'s 1 through 3. 
(1 2 3 4 5    1 2 3 4 5    1 2 3)

6) e|-7-7-7-7-7-7---7-10-9-8-9---8-7-6-7---------7-|
   B|-------------6------------9---------7-3-5-7---|
   G|----------------------------------------------|
   D|----------------------------------------------|
   A|----------------------------------------------|
   E|----------------------------------------------|

7) e|-7-7-7-7-7-7---7-11-10-9-10----9-8-7-8---8----|
   B|-------------6--------------10---------8---7--|
   G|----------------------------------------------|
   D|----------------------------------------------|
   A|----------------------------------------------|
   E|----------------------------------------------|

Play #'s 6 and 7 three times. 
(6 7   6 7   6 7)

8) e|-----------------8-9-11-8-6------------9-8-9-|
   B|-8-9-8-9-11-9-11------------8-11-10-11-------|
   G|---------------------------------------------|
   D|---------------------------------------------|
   A|---------------------------------------------|
   E|---------------------------------------------|

9) e|--------------------9-10-11-9-7----------7--------|
   B|-9-10-9-10-12-10-12----------------9-----------10-|
   G|--------------------------------------------------|
   D|--------------------------------------------------|
   A|--------------------------------------------------|
   E|--------------------------------------------------|

10) e|------------------------------------------------------|
    B|-7-8-10-8-7-5-------5-6-8-6-5-3-------3-4-6-4-2-0-----|
    G|--------------7-6---------------5-4---------------2-1-|
    D|------------------------------------------------------|
    A|------------------------------------------------------|
    E|------------------------------------------------------|

Play 8 through 10 one time. Play 6 and 7 again. Repeat 8 and 9. 
(8 9 10   6 7   8 9)

11) e|----------------------|
    B|-7-8-10--5----4-5-7-3-|
    G|----------------------|
    D|----------------------|
    A|----------------------|
    E|----------------------|

Play # 11 twice. Then play 6 and 7 again. 
Then, finally, play #'s 1 through 3 to end the song. 
(11    11    6 7    6 7    1 2 3)

And that's it! The end!

- mEgAn