If you are trying to sell PBX's, inside cabling/wiring for new office growth/expansions, and telephone services (T1, MetroE, MPLS, VPN) and jsut starting out - go to Sales Genie.com or another type of service, hire a telemarketing firm to generate leads or buy solid leads from a third party. You can also buy new business listings from the city (some listings are provided for free) and start calling these businesses. Of course you can always go door-to-door but that never covers as much ground as using the telephone. Goiing door-to-door only works if you know a potential customer is moving or expanding their business. And when calling always have an establish script in place before calling - make sure you know what you are after before dialing. Not sure if this is what you are after - good luck.
brought to you by John Parks answer on LinkedIn.