MXtoolbox (disclosure: I hold no relation to this site) has a great blacklist checking tool that checks all the major blacklists.
As for staying off them, make sure all your e-mails are opt-in and have an unsubscribe link within the e-mail body of every notification sent. Keep a record of all clients opting in, some hosting companies will charge you a small fortune if you get their IPs blacklisted.