Never mind the slightly goofy cover, this is the shredder's bible that is guaranteed to take you from 40 to 200mph in 6 months.
Intense Rock was the first of Paul's REH videos (VHS format) that was released in 1988. Back then shred guitar had only been around for a few years and except for a few naturally dextrous individuals, it was still largely in the realm of 'how-the-hell-do-you-do-that' for most guitar mortals.
Within several months of the release of Intense Rock I, it seemed like everybody and their little brother had jumped onto the shred guitar bandwagon and had attained amazing technique. PG's video was the tipping point.
Intense Rock I is purely about geometrically mapping out the fingerboard into speed picking friendly shapes, learning them as small groups of 3 or 4 notes and then expanding them throughout the various octaves on different string groups. Also covered are legato patterns -- "let's say hello to the left hand" -- and string skipping ideas in lieu of sweep picking.
1991 saw the release of Intense Rock II where Paul discussed dynamics and phrasing alongside technical ideas that were mostly variations of what he had already talked about in the first video. He also clarified a few points on important topics he felt he had inadvertently left out previously such as using pick accents to develop better rhthmic control and accenting in various rhythmic groupings.
Fast forward to 2006 and Alfred Publishing has released both videos in one 2-hour long dvd. And even if you're not an aspiring shredder this dvd set will help your overall technique no matter what style you play, and perhaps even give a few insights to better fingerboard visualization.