Norton has got very few fans (either here on AB or in the computer press). Whatever choice you end up making, it's likely that you'll want to get rid of Norton. You can't uninstall it from 'Add/Remove Programs'. You'll need this tool:
http://service1.symantec.com/Support/tsgeninfo .nsf/docid/2005033108162039
Kaspersky is generally far better reviewed.
I know nothing about NOD32 but I do know that the vast majority of the regular contributors to AB's Technology section don't use any commercial software.
Most people here seem to be satisfied with the free version of Zone Alarm as their firewall. (Comodo is also widely praised).
The majority of AB-ers have used the free version of AVG, up until recently, as their anti-virus solution. However, there's been some dissatisfaction from some (but not all) users in respect of the latest version, resulting in many people switching to Avast!
Lastly, AdAware and SpyBot are both well-recommended anti-spyware tools.
Definitely get rid of the dreaded Norton. Then either install Kaspersky or join the majority of us and use the free stuff.
Chris
PS: Last year, PC-Pro magazine summarised NOD32 as 'an eccentric package that gives only average protection'. Kaspersky topped their ratings:
http://www.pcpro.co.uk/labs/155/antivirus-soft ware/products.html