If you are working with a large brokerage firm, find out if you will have one stockbroker that will work on your specific investment plan. This provides you and the broker to gain an understanding of how each other works plus it makes communicating your needs or investment goals much easier.
Since choosing a stockbroker is a very important decision and one that will drastically change your financial situation, you need to interview several and talk to them one on one. Do not buy their salesmanship, but find out what they can do for you in writing and on paper. Make this decision based on the skills they can provide to you.