To save a few bucks, I buy PFW's pre-draft issue (end of March) instead of their more expensive
(and less recent) Guide.
I also wait for USAToday's Sports Weekly draft issue (early April); it's a little more expensive than its regular weekly issue, but it comes individually wrapped and is much thicker.
I always buy Lindy's pre-season mag (the best on the shelf, IMHO), but its pre-draft issue is just info from NFLDraftScout, who also provides for Sports Weekly & CBSSportsline.com.
I also buy The Sporting News draft issue, but use it more for reference than for gospel
(which I guess would make it the Wikipedia of NFL draft mags).