There is a generally accepted format used when writing a PhD thesis. It is a good idea to adhere to this format unless instructed otherwise. The PhD thesis structure will be as outlined here:
If you find PhD thesis writing stressful and time consuming don't worry; you're very far from being alone. It's a big job and one that has to be done to a very high standard, which all takes time. Unfortunately, when you're getting towards the end of a PhD course, time is one of the things you don't have much of. That problem becomes even bigger if you're not a very confident writer, because things that would be easy for a professional are going to need more than one attempt to get them right. Even then you're not guaranteed the result you need. The fact is that writing a PhD thesis is difficult and not everyone can do it to the standard required. It can seem unfair to suffer for writing ability when you've done an outstanding job of the research needed for your thesis, but there's not a lot you can do about it; either you can write well or you can't. It's possible to improve your ability through practice, but when your thesis deadline is approaching it's a bit late to consider that.
Writing a PhD Thesis | PhD Thesis Bangalore
Keep in mind that your mind map for the thesis does not only include PDF links but you can write complete sentences. Again, have a look at the picture to get an idea how your final mind map should look like. Now, read in the third part how to finally write a phd thesis.