Of course the better business bureau is a wonderful source, but an even better source would be people who have actually done business with new client.
And most important of all - don't be afraid to get partial payments up front. This guarantees that if you get stiffed, at least it won't be for the full contract.
In the two years, that we've been in business, we've only run into one client who dinned on our services and dashed without fulfilling the obligation of his contract. We signed the contract based on the fancy talk of a big talker who pretended to be a well heeled financier.
What a lesson! After the contract went unpaid for almost six months, we did some investigating. Friends who knew him personally and professionally said that he made a practice of skipping out on bills. If we had done the due diligence before hand, we wouldn't have been left holding the bag.
TRUSTing is good VERIFYing is GREAT!