Matt Cutts from Google explains how search works (3:15).
For some of your topics, doing a search on Google will be beneficial. Many colleges, universities, and academic libraries have topical guides that can help students with genre-specific writing. You might also find blogs or websites devoted to genre-specific writing.
Here is a way you can search for content from websites that end with .edu. You can do the same with any domain, such as .gov, .mil, .com, .org, etc.
(write or writing) AND resume* site:.edu
Here is a way you can search for research guides from university and college libraries. LibGuides is a popular platform for building online research guides. The guide for your class, for example, was made using LibGuides.
(write or writing) AND resume* AND libguides
It might be helpful to do searches with the phrase "best practices," too.
(write or writing) AND "social media" AND "best practices"