The items should be nicely arranged and laid out on open shelves for the child to easily take an activity off the shelf to use. Once an activity is done, the child should always put it back where it belongs. In this way he is taught order and respect for things. My daughter got the hang of this very easily. Rather than leaving all her toys out on the floor, she really has taken to putting them away where they go when she is done. She doesn't do this all the time by herself but she will if I ask her.
If you don't have a specific room that can be used for school you can also used a roll away shelf that can be rolled into a closet when not in use.
I personally live in an apartment at the time and don't even have the luxury of doing that. At the time I have some Montessori activities tucked away in a back hallway on a shelf, it is not ideal but it allows my daughter to be able to work with what she wants and put it back when she is done.
Next week I will touch on how to introduce activities to your child and give you a few activities I have used with my daughter.
If there are any questions about the posts thus far, please don't hesitate to ask, I love comments!