What happens when you report abuse on WikiAnswers?

Answer 1

Reporting AbuseWhen you click on the red "report abuse" option on the top right side of the question and answer page, it sends the report to the appropriate people who will investigate it for obscenity, inappropriate content, etc. If they determine it to be any of the above they take appropriate action, which can include a warning, a temporary block, or even a permanent block.

And how do you actually report spam or abuse?

See the detailed information in the Related question.