Your best option is to watch the video's in the OP (edit: It wouldn't hurt to read the OP from top-to-bottom, either!). If you are familiar with BF2, you will have no problems picking up the mechanics of this game. The most different thing at this point, is that we have only played the Rush game mode, which opens up small sections of the map at a time. When the full game comes out, you will be able to play the regular old Conquest mode from BF2. The major things missing from BFBC2 vs. BF2 are Prone, Jets, 32 max vs 64, and commander. It adds several new game modes, a single player campaign, destructible environments, and customizable weapons. Other differences you will pick up easily enough over time.