some more books, free and legal
The Amiga. Images, Sounds and Animation on the Commodore Amiga
Michael Boom
http://bookos.org/dl/1279782/f4dc4a
Amiga Programmer's Handbook, Volume I
Eugene Mortimore
http://bookos.org/dl/1359704/138751
Amiga Programmers Handbook Volume II
EUGENE P. MORTIMORE
http://bookos.org/dl/1393619/13ebf4
The Amiga Guru Book: A Reference Manual
R. Babel
http://bookos.org/dl/1399631/05f900
AmigaDOS Manual Third Edition
Commodore-Amiga Inc
http://bookos.org/dl/1403773/a6b869
Amiga ROM Kernel Reference Manual: Devices
Commodore-Amiga Inc
http://bookos.org/dl/491275/18af34