Half of them don't even have an e-mail address, no 800 number. Those that had pictures and e-mail addresses where I could inquire about availability and make a reservation got my attention. It helps to have an interactive forum - if you want more information about this product or service, click here. But you need to have people ready to respond to those who contact you. Otherwise it's like having a telephone in your office and not answering when it rings.
Someone has to be assigned responsibility and given time to respond.
That depends on your objectives. You can just put your company information up there and let it collect dust. If people want to know more, they e-mail or call your company. That's the very lowest level of Web site development, but it still can be valuable. Also, I devote one whole chapter of my book to analyzing web site traffic.