Get experienced advice from the beginning. Don't rely on someone in the office who just learned HTML and has a personal web site to produce something that will give the right image of the firm. Start right and end right. It's time consuming . Planning takes time.
Design takes time.
Reviews take time. Revisions take time. Maintenance takes time. Responding to the requests that come in from the web site takes time. Creating the new materials needed to put up on the web site regularly takes time.