Norton is a suite, it attempts to give you protection for many areas of the PC. That is firewall, anti-virus, anti-spyware, email scanning, real-time protection.
If you choose to go down the pay-for route Kaspersky is an excellent choice:
http://www.kaspersky.com/
However all the protection I use is free, although I have donated to some of the projects, here is a list of free programs for you to choose from. You will need 1 anti-virus program, 1 firewall, as many anti-spyware as you wish.
For your needs I would choose the following because they are easy to setup:
Firewall - Kerio or Zonealarm
Anti-virus - AVG or Avast or Anti-vir (no email scanner)
Anti-spyware - AVG anti-spyware, spybot S & D, adwareSE personnal
you might also consider Winpatrol:
http://www.winpatrol.com/
Hope that helps you out