This is up there as one of the most requested songs songs that students want to learn. Just about every new student that comes to me can already play a little of the intro to this song. Like most Metallica songs there is always parts that a keen beginner can play, but then you'll have sections on the same song where even an advanced student will have trouble with.
Because this song is so involved I have broken it down into 4 sections. Parts of this song have been adapted so that two guitar parts can be played as one. If you want to learn the correct single guitar parts I would suggest you go and buy the sheet music, I have always found Metallica notation/tab books to be spot on accurate.