DUI is a sensitive subject, so you might not want to try networking to find a good lawyer as you would with other fields of law. Try the Internet instead; you should be able to find dozens of DUI lawyers in your local area, and even more if you live in or near a large city.
Some websites, like Yahoo Yellow Pages, allow people to review the quality and services at various businesses. Why not use that for DUI lawyers as well? At the very least, checking to see what other people have said about a lawyer can help you narrow down your list of candidates.