Unless sent via a cookie, I can't see how you could become infected just by surfing.
Some Warez downloads contain viri and email is the main culprit. Again, a full time scanner should prevent either unless you executable and then if that is an attachment a good proigram will detect that as long as the pattern is up to date.
In your case, I'd run the AVG you have, then go to the link I posted and let it scan your system as well. Nothing is 100% effective.