General
http://nms.gdd.net/index.php/Main_Page
http://docwiki.cisco.com/wiki/Internetworking_Technology_Handbook
SNMP
http://docwiki.cisco.com/wiki/Simple_Network_Management_Protocol
Books
http://www.amazon.com/SNMP-SNMPv2-RMON-Practical-Management/dp/0201634791
http://www.amazon.com/Network-Management-Principles-Mani-Subramanian/dp/0201357429
http://www.ciscopress.com/bookstore/product.asp?isbn=1587201372#