Not only is this a metal classic, it is one of Maiden's easier songs to play. A lot of non-Maiden fans still have a soft spot for this song. It is fast, but that speed will come with practice. The chord changes are relatively simple, and there are only a few song segments to learn:
Intro - While the lead guitar plays the high bends the rhythm guitar just plays this series of simple powerchords and double stops.
Verse - This is surprisingly easy once you get the hang of it. There are only a few chord changes, but there are 2 important things to point out:
1. Powerchords are played using your 1st and 4th fingers (NOT 1st and 3rd). Sometimes bands play powerchords this way. You should also follow suit in this song because you will find this finger stretch much easier.
2. Galloping. This is the bread and butter of Iron Maiden's playing style. Notice the rhythm of the palm muted D5 Chord. It has a kind of galloping sound. This is achieved by using triplets. A triplet is where you play 3 notes (or chords) in the space of 1 beat. After the first palm muted downstroke, start using triplets. This is done by playing down / up / down strokes quickly each time. Watch the ActionTab, listen to the sound, then take it to your guitar. Practice getting tight and build up speed only when you have the technique consistent with that first D5 chord. The rest will flow much quicker then (and you will also find many other Iron Maiden songs easier to play).
Chorus - Simple open Powerchord stabs. Stick with the 1st and 4th fingers, because you'll need to do that finger stretch again.
Solo Backing - Again, quite simple and repetitive stuff. But you'll need that galloping technique down.
Interlude - Gotta love this bit. Bruce's singing rules. Switch to using palm muted downstrokes and open chord strikes.
Outro - Just belt away at the last C5 chord and take a bow. You've earned it :)