It is far better to have published a few papers of high quality that are widely read than

it is to have published a long string of minor articles that are quickly forgotten.

The only way to find out how to do a PH.D is to do one.

Therefor, all advice are useless.

This pages have some valuable links on how to be a professional researcher.

Some Modest Advice for Graduate Students
Write good papers
You and Your Research
A complete guidance for the graduate students
Advice Collection