I would think the HOA would want to create the local area network independently from AT&T. They HOA should be able to install conduit underground, run electrical power and fiber or Ethernet connections to each pole. Send all the data connections back to an equipment room. Why get AT&T DSL involved with that? If you wanted to do part of it with wireless connections, you can do that also.
Ruckus Wireless »
www.ruckuswireless.com/ might be able to help design a wireless network to meet your needs.
As far as getting the camera images to the World Wide Web, that depend on exactly where you are located, and what internet services are already available. If you are in the correct location, AT&T or some other enterprise level ISP might be able to connect you to a 100Mbps symmetrical internet access fiber optic line, for a price. If you are not close enough you might have to pay a few hundred thousand dollars to get one installed. Or several million dollars.