Watch the Hard Rock online guitar lesson by TrueFire from Play Rock Guitar 4: Rhythm Principles
In this section you will work on a variety of different Hard Rock concepts. Many of the techniques you will work on here like triads and syncopated rhythms will flow over to other styles, so it isn't just about the hard rock vibe - it is really about learning the details and then applying it to all of your rock guitar playing.
TIP! Everything you work on should be started slowly, paying attention to the fine details of finger placement, minimum motion, efficient picking hand movement, and proper intonation. Then GRADUALLY increase your speed. Think baby steps. Don't try to jump from zero to 60 - take it slow. As you gradually speed up you will see other technique issues that need to be addressed. These are more easily discovered and dealt with at slow tempos. It is way harder to fix a problem that you have burned into your muscle memory than it is to just start slow and fix things along the way. So always start practicing a new thing slowly, and then build up your speed.