A very interesting website for those who know street and house addresses for their families in Wroclaw during the Prussian time. This site has old photos of street addresses and also many architectural house plans. These are written in the German language and many date prior to WWII. Not all house numbers are represented here, but it is definitely very interesting to see.
There is a architectural newspaper covering the years 1903-1942 for Wroclaw/Breslau at this link. These newspapers write about building plans at various street locations and the architect over the project and other interesting materials.