Some good books for learning North American hawk identification are Brian Wheeler and Bill Clark's A Photographic Guide to North American Raptors (great photography), Dunne, Sibley, and Sutton's Hawks in Flight (learn how merlins are like Harleys, not scooters), Liguori's Hawks from Every Angle, and Clark and Wheeler's Peterson guide to Hawks. An excellent overview of hawks and hawk migration for beginners is Clay and Pat Sutton's How to Spot Hawks & Eagles. Quite often flight style and behavior are better clues to ID than traditional "field marks", so books can only take you so far.
The best way to learn about hawk migration is to visit a hawkwatch near you (or if you don't mind crowds visit the famous Hawk Mountain Sanctuary). The Hawk Migration Association of North America (HMANA) is an organization of volunteers interested in raptors and their migrations. HMANA gathers data from hawkwatches around the U.S., Canada and Mexico into a central database hawkcount.
BBS and CBC distribution maps for golden eagles (BBS does not include the eastern Canada population):