If you are in the process of writing your proposal, I truly recommend “Proposals That Work” book. As someone who was not used to academic writing, this book has been a great help. It’s more toward the quantitative research but even if your research is qualitative it still can be useful. My adviser recommended this book and so far it has been a great help. I got a used, in good condition book, and I believe I will keep it for the years to come.
Also, it goes well with good cup of cappuccino.
Another great book if you are doing human base research is “Research Methods in Anthropology” by Russel Bernard. You will get very good insights on different ways of approaching people. Different questionnaires and different surveys. I also enjoy every book which points out feminism or indigenous cultures.
I took people out of my research but I still enjoy reading this book as reference.
Also, I like how author has done his research in Greece. Every time I read his examples, the cultural similarities makes me laugh.