I need a list of good metal songs learn starting at a beginner/beginner-intermediate level.

I’ve been teaching myself guitar for about a year now. I’ve mainly been using a combination of Hal Leonard guitar books, online lessons from sites such as justinguitar.com, and patching together whatever knowledge I gain from websites and magazines. The problem is that although I understand the importance of learning to play a variety of songs in different styles (and will continue to do so) the type of music I wish to learn to play the most is metal. And none of those sources offer a selection of metal songs to learn where the difficulty gradually ramps up starting at the beginner level in the same way they do with songs of other styles.

Is there a resource available where songs are listed in ascending difficulty or are ranked by how hard they are to learn that also contain a strong selection of metal for every level? If there is none could you guys suggest some songs for each difficulty level. The range of metal I like features artists such as Black Sabbath, Iron Maiden, Arch Enemy, Lamb of God, Dethklok, Dimmu Borgir, Slayer, Dream Theater, Pantera, etc. I’ve tried picking songs on my own to learn but they either are way too easy or, as the case usually is, way too hard.

As a side note I have noticed the Beginner Song Program sticky at the top of the page and suspect that it may be related to what I am looking for. I have no way of knowing for sure though as I was completely and thoroughly confused when I clicked the link and there is no guide on how to use it or explain exactly what it is.
I've made a list for the songs from the artists that you like.

Beginner, from easiest to hardest
Iron Man by Black Sabbath
Paranoid by Black Sabbath

Intermediate, from easiest to hardest:
Overture 1928 by Dream Theater
Laid to Rest by Lamb of God
Number of the Beast by Iron Maiden
Run To the Hills by Iron Maiden
Cowboys from Hell by Pantera
Thunderhorse by Dethklok

Nemesis by Arch Enemy
Any Dream Theater song with a high speed alternate picked/sweep picked solo (fatal tragedy, constant motion etc.)

Difficulty is subjective though, so you may find some songs easier/harder than others.