Articles or books by an attorney may indicate the depth or spread of an attorney's knowledge. Be careful in selection since these do not guarantee success or ability. An attorney does have a license to protect and is subject to discipline for incompetence or neglect. This may give you some comfort. An attorney can represent a person before the Immigration Service.
All notices go both to the attorney and the client.
Some specialize in investments and investor visas. Some are hard working, knowledgeable and competent. Some are former employees of the Immigration Service or are former U.S. consular employees. Because there are no uniform examinations or licenses needed, it may be difficult to determine the background and experience of a consultant. The best recommendation is a personal referral from a satisfied client.