Re: How should I start learning to play guitar?
In my opinion it's always best to start in the following way
1) Learn a few basic chords and chord progressions. e.g. C, D, E, A, G
2) Learn how to strum these chords in a nice progression
3) Learn a simple song using tabs... e.g. Oasis - Wonderwall [I think the first song I ever learnt]
4) Learn a few more "easy" songs
5) start building up technical ability with a metronome, learning a scale and playing it to the beat of a metronome over and over
You will quickly get bored unless you learn a song end-to-end I think... since you're into metal it will be difficult to find a decent song to learn at the start as they will be tougher than other genres.
Some decent metal songs I learnt to start with, that weren't too technical:
Papa roach - last resort
system of a down - sugar