The Tor website has some excellent tips for running an exit node if you want to do so:
Inform your potential ISP(s)
In general, running an exit node from your home Internet connection
is not recommended, unless you are prepared for increased attention
to your home. In the USA, there have been no equipment seizures due to
Tor exits, but there have ...
Don't use your private home connection for running an Exit node! Exit nodes are blocked heavily and can expect many attacks. If you still want to use your own internet connection for normal activities like browsing or sending e-mails then allot of services will block you because they know your IP address is also running an Exit node.
Instead of running an ...