The air combat bible:
http://www.amazon.com/Fighter-Combat...fighter+combat
Used: $13.74
Got mine in 1998 for $35 new.
More than half is on missiles. You don't need to read those parts for IL2 but do read the preface as it tells how to take and use what is written.
Warning: that book reads like chewing through bricks. It is a technical book, has no nonsense or fluff.