Why, exactly, are we trying to do something? That should be the first question you always ask yourself. My typical approach is to gather a high-level overview first; this way, you never lose sight of the big picture. So, at the high-level overview, we want to track rental units, who's renting them, and whether or not they have paid up. Then, you should get into slightly more specific details. On a more in-depth look, we'd also like to know who actually owns the unit, whether or not it's part of a complex system, what additional fees (if any) are accumulated, possibly take a look at vendors who render services to the complex, as well as payment information. Finally, the actual data elements (fields) that we need to collect in order for our app to be as useful as possible and keep the accountants off our backs by offering a high return on investment on licensing/development work. We'll cover fields a little later. For now, let's take a look at the key things and people/entities involved...