eNotes does, in fact, have a study guide that should find very helpful, both in terms of understanding Bruce Hoffman's book, Inside Terrorism, and in gaining a better grasp of the subject overall. A link to that study guide is provided below.
Hoffman's study, originally published in 1998, was updated in 2006 to take into account the terrorist attacks on the United States on September 11, 2001. Inside Terrorism is a well-respected academic study of the phenomenon of terrorism. Briefly, Hoffman traces the history of terrorism over the centuries to demonstrate the patterns of activities and motivations guiding the terrorists' actions. Hoffman's global coverage and insightful analyses of various terrorist movements around the world and across time provides a comprehensive look at the problem of fighting terrorism -- fighting not necessarily in the sense of using military power, but fighting it politically and economically. Particularly illuminating, although hardly unique to Hoffman's study, is the discussion of terrorism emanating from causes with which many Americans and other Westerners are sympathetic.