This link on PhD Experience is shared by my friend missa who is going to do her PhD soon.
This article is good. It's not just suitable for people about to embark on PhD but also suitable for us who are struggling in our PhD journey.
Some valuable excerpts:
Learning how to do research
There is no recipe for good research. Some students expect or hope to be provided with step-by-step instructions or guidelines on how to find or tackle problems. That's not how it works. Here are a few indications of what is involved.
Learning by thinking
The first rule of research is to think, think and think again. Never hesitate to throw your mind at anything. That should be the first thing you try. Before looking up a book or paper, before asking anyone, think. For example, suppose you are reading a paper and there is a lemma, with the proof referred to another paper. Should you go get the other paper to look it up? No. First, try to prove the lemma yourself. If you don't succeed after a reasonable time, go look it up. But if you solve it yourself, you will have understood it better. What you solve by thinking is your baby from then on; what you look up you will forget and have to look up again and again.
Never be lazy about thinking. That's how you build up understanding and develop a bag of techniques that you can use.
Thinking is fun. If you don't find it so, it's an indication you are in the wrong business.
Learning by example
You pick up how research is done by seeing examples and extrapolating. Papers, and discussions with your advisor or peer, are a source of materiel. You learn how to write a paper by looking at other papers. Make anologies. When you see a new primitive or problem, ask yourself what kinds of questions were asked about previous ones and use that to ask questions about the new one.
As you go on, you should be able to extrapolate more and more, and farther and farther.
Understanding versus knowledge
It is more important to understand well what you know than to know a lot. Successful research comes from having a good understanding, especially of the basics.
When you read a paper, ask yourself questions. What if I changed the scheme in the following way: would it be secure or not? How does this compare to the following other scheme? Why is this novel? Can I come up with a different proof? Understanding means the ability to go beyond the immediate. It means knowing not just what is the item in question, but how it fits into a larger context, what are its variants, and what happens if you ``perturbe'' it one way or another.
Gauging progress: am I on track?
The best way to know is to ask. Progress is measured in a number of ways. Direct output, like papers is the most obvious. I also look at how your understanding and knowledge of the materiel is developing.
What is enough?
The minimal Ph.D is probably about four papers, but there is no hard and fast rule. Sometimes you may have stronger papers, or a larger contribution to co-authored papers than in other cases, in which case fewer papers may be enough. In other cases you may have more minor results or a lower contribution to co-authered papers, in which case you may need more.
Remember if you want to head into research, whether at a research lab or in academia, they will look at your publication record, not your thesis, and you want recognized publications and exposure in the research community.
In addition to papers I expect you to develop communication skills, both written and verbal. You should be able to plan and give clear talks and to write clear and correct technical papers. There is no under-estimating the importance of communication.
There's more in the article. So do take your time to read it :)
