I think I answered a similar question by you, but just in case...
Cottage rentals are quite rare in Silicon Valley.
Many of the areas with cottages are older (homes are 60+ years old) and can be found in Willow Glen, downtown San Jose, and sometimes in Los Gatos, Campbell and Cambrian areas, not too common in Cupertino, sometimes in Mountain View.
There is no "cottage rental list" I'm aware of, however I can set you up on an automated search designed to find these types of properties as they come up.
What is your rental budget and timeline?