As mentioned in the first answer, you will not be breaking the second law of thermodynamics because you are investing effort (expending energy) to increase order.
Entropy can be loosely defined as a measure of chaos, and the second law of thermodynamics states that the chaos of the isolated system always increases. External force (from a source of energy) has to be applied to the system to reverse the process.
You can clearly see the second law of thermodynamics at work when you consider how quickly your room becomes messy without anybody conributing effort to make it this way. The entropy, the measure of chaos, or disorder in the room, always increases.
The second law of thermodynamics states that the total entropy of an isolated system cannot decrease.
Putting this in the context of your question, if you were to leave your room locked, things in your room will not automatically move and rearrange themselves in a more orderly fashion. With time, everything will move to a more disordered state, for example food and other organic products will start to rot, even the condition of inorganic products will start to deteriorate as the particles that they are made of take on a more disordered state.
When you clean your room you have to expend energy. It is this energy that is responsible for decreasing the disorder in the room.