hey. i use avg antivirus. and spybot and adware. they all seem to have a quarintine or delete option. im assuming that delete is the best way to go. am i correct. if so when do u quarentine?

Yup you are correct. Though you can use quarantine when unsure what the virus does. That way you can submit the sample to the av software producer, when the virus is unknown.
Bram

Quarentining is also good incase it might be a fasle positive so that you can restore the file if needed. Watch specially for words like "Heuristic" in the detection warning , it might be a legit file that you need.

If you quarentine them then you have a change to see if anything "bad" happends to youre pc , if you delete them immediatly then you cant do that. And you can always delete the quarentined items later.