Typically, these meetings are used to discuss business issues around the game. However, the evenings are often used by the baseball operations people to set the foundation of their off-season agendas with other teams. They could use this time to gauge interest in players they might look to trade or trade for as well as initial discussions for free agents with player agents. Typically, there aren't many moves made during these meetings, although thanks to the advent of Social Media and up-to-the-minute reporting, there are a ton of rumors which now come out during this time.
This year, one of the issues teams have - especially those looking to invest in the top of the free agent market - is that players who were given a qualifying offer have until November 9 to either accept or reject it. That is the last day of these meetings, and so the field of free agents won't be finalized by the time these meetings start.
The craziness will likely start after these meetings and during the Winter Meetings, which are taking place between December 4-6 in Nashville, Tennessee this year. The Winter Meetings are actually is a Minor League event, but Major League executives and front office members congregate in the venue's hotel suites and use this time to focus on player movement. The lobby of the hotel is typically filled with beat reporters, national sports writers, agents, managers, current and former players, and television crews all soaking in the craziness of the event. The best way to describe the atmosphere of the Winter Meetings is that it's basically like one giant poker event, and everyone is playing against everyone else with their own unique poker faces on. It's fascinating to watch the agents circulate around, listen to the discussions managers and players have, and so on. Hundreds of vendors also occupy the event and form a convention to sell their various game-related gadgets, technologies, etc. for teams to use at the ballpark and in the clubhouse.