Some "must have" books...

• MILLENNIUM STAR ATLAS - 3 volumes - An all-sky Atlas comprising one million stars to visual magnitude eleven and ten thousand non stellar objects, (c)1997 Sky Publishing Corporation https://en.wikipedia.org/wiki/Millennium_Star_Atlas
• Sky Catalogue 2000.0 Volume 2 (c)1985 Sky Publishing Corporation
• Deep-Sky Wonders by Sue French (c)2011 Firefly books Ltd.
• Astronomical Algorithms by Jean Meeus (c)1998 Willmann-Bell Inc.
• The Handbook of Astronomical Image Processing by Richard Berry and James Burnell (c)2001 Willmann-Bell Inc.