Hello, and welcome to OpenStreetMap!

There are actually several methods for adding an address to OSM, depending on how much effort you want to put in.

  1. The most detailed approach is to trace the outline of the building from the background images, mark it as a “building”, go to its address tab and enter the address. This is an example from your area.

  2. A less detailed variant is to do the same as above, except you don’t draw a building outline, but only put a single node somewhere within the building. This would be quite similar to placing a POI for hotels or other amenities.

  3. Finally, a third option is address interpolation. This is somewhat different from and more complex than the others, so it might be a bit overwhelming for a beginner. I’m mentioning it anyway for the sake of completeness, and because it is used by some who want to add a large amount of house numbers very quickly and are not interested in per-building accuracy. Using this style, you draw a line from the first to the last building within a sequence of house numbers. You add addresses to the start and end point as in variant 2. But then you select the line between the two points, switch to the “advanced” mode of Potlatch 2, and add a tag “addr:interpolation=all” (if all numbers between the first and last can be found on that line), “addr:interpolation=even” (even numbers only), or “addr:interpolation=all” (odd numbers only) to the line.

By the way, I fully agree that adding addresses is a common use case and should be made as easy as possible by Potlatch.