All of my work is either word of mouth or contacts from years of doing work. A website is a really good idea now days even if it is simple, it seems that everyone wants to check you out. If you are doing mostly residential type stuff the phone book is good. Otherwise for commercial or new construction call builders and just ask if you could be put on there bid list.
There are lots of free places online for potential customers to find you. Google Places, Yext, Craigslist , and many others. Yellow pages are very expensive and now a days is ineffective advertising IMO. Word of mouth is always best.