You should start with the FAQ, if you haven't already seen it:
https://www.torproject.org/docs/faq-abuse.html.en
The topic has been addressed many times on the list as well, so I'd suggest searching the archives. You can easily do that via Google with a search like:
You can reduce the abuse to some extent by using the recommended reduced exit policy. You'll probably get a decent amount of reports anyway. Don't run an exit from your home.