After location, the most important decision that you will need to make as an event organizer is regarding internet solutions. A robust connection is largely just assumed at this point in time, since most of what will need to be done in any industry will depend on the internet at this point.
Many venues have installed hard-wired systems into their facilities, but these may not be up-to-date, and they may also be too expensive. For ISP rental, go to Trade Show Internet. They have premier, portable solutions, including the Xirrus system of WiFi. With their CONNECT service, you get not only the Xirrus system, but the engineering experts to ensure it is properly set up for you, and the on-site Network Operations Center to provide monitoring of your network in real time.
They have services coast to coast. For more about their operations on the west coast, go to http://tradeshowinternet.com/eventorganizers/san-francisco. To access their services in NYC, go to http://tradeshowinternet.com/eventorganizers/new-york.