The place where you should look for material, depends on the type of subject. Publishers, specialist literature and websites usually provide the best results.
For some types of materials, there are specific sites.
And then there is of course (the rest of) the Internet, where a multitude of potential learning materials are available.
How to find and assess your learning materials on the Internet?
There are sites that collect educational learning materials. You can search materials based on categories and meta data. Metadata is data that describes the characteristics of certain data. It is actually data about data. Metadata in a certain document (data) may include: the author, date of writing, the publisher, number of pages and the language in which the data is provided (source wikipedia). As a teacher you can usually also share content (like you can do, for example, on- YouTube). There is no real peer quality control then, but through a ‘voting’ system, users of the site do give a certain assessment.
Additionally, you can use a search engine like ‘Google’ and search for information suitable for you.
In the learn more section, you will find more sources on how to make your search as efficient as possible and on how to assess the quality of a resource.