Hopefully, your colleague also gave you a vague idea of what you're going to be *doing* with SNMP. The purposes it's going to be used for will have an impact on what you set up, and how.
Anyway, here's a good link:
http://www.debianhelp.co.uk/snmp.htm
The odds are pretty good you don't even need to download anything - "net-snmp" is probably already available on your basic distro. Just go into your package manager and look for "snmp".
Please post back (opening new threads) with any specific questions you encounter once you get started.
Hope that helps .. PSM