I think resource requests should be treated, for the most part, like list questions. If there is a way to produce a finite, best quality list of resources, then the question is good. If the only problem is that the list might increase over time, it might be worthwhile making a community wiki question. Otherwise, it should be closed.
These types of questions should be careful to cite the resources as fully as possible (title, author, publication data, etc.) so that it is possible to track down the resource (links to amazon pages or other webpages showing the resource are not sufficient because they are subject to link rot). For web-based resources, check the Wayback Machine and make sure they are cataloged before adding to the answer. This way if the pages go down, there is a backup reference.