Myth: You do not need a wedding planner. The location/venue/catering manager will help me.
Truth: Simply speaking, a location manager is not the same as a wedding planner. The location manager works for the venue and the wedding planner works for you! The three of you (+ the groom) should work together to ensure your wedding runs smoothly.
That said, it works differently at all locations, so you cannot make assumptions. There are venues where the location managers (sometimes called a catering or site manager) will work closely with you on all details from the moment you book the location until you leave the reception as husband and wife, offering vendors referrals, advice, and suggestions to assist you. Still, some venues work with a more hands-off approach, assisting you with details related to the venue (pricing, menu, times) and nothing more. In many instances, the location manager is onsite for the beginning of your wedding to ensure everything is ready to go but may leave sometime after the reception begins, leaving you in the hands of the banquet captain.
A wedding planner works independently of the venue and is hired by you, to be your advocate. Now, depending on what services you hire a wedding planner for, she can be available to accompany you on appointments, taste menus, assemble invitations, run errands, or to simply manage the wedding day. (Check back later in the week for the skinny on the different types of wedding planning services!)
So, don't get the services and responsibilities of wedding planners and location managers confused. Lastly, don't be surprised...ask questions, specific questions. Be sure you understand the extent of the assistance your location manager offers.
P.S. I always recommend the services of a professional wedding planner.