How to write a good mathematical paper? I hesitate to ask this question. However I read many advices from math.stackexchange, and I couldn't find anything similar. 
A good time always goes too fast! Two years are fled. In the third year of PHD, my major is general topology and I'm facing with graduation from PHD. I do enjoy research, however the pressure to publish makes me be agitated and not quite, for I haven't publish any paper. I find, sometimes, doing research and to publish are contradictory.
Here is my question: How to write a good mathematical paper? Could anybody give me some suggestions? 
Thanks ahead.
 A: I would like to add the above mentioned Paul Halmos work on How to Write Mathematics.
In too short (taken from the MAA):

  
*
  
*Say something. To have something to say is by far the most important ingredient of good exposition.
  
*Speak to someone. Ask yourself who it is that you want to reach.
  
*Organize. Arrange the material so as to minimize the resistance and maximize the insight of the reader.
  
*Use consistent notation. The letters (or symbols) that you use to denote the concepts that you’ll discuss are worthy of thought and
  careful design.
  
*Write in spirals. Write the first section, write the second section, rewrite the first section, rewrite the second section, write
  the third section, rewrite the first section, rewrite the second
  section, rewrite the third section, write the fourth section, and so
  on. (Annotation: 1,2,1,2,3,1,2,3,4,...)
  
*Watch your language. Good English style implies correct grammar, correct choice of words, correct punctuation, and common sense.
  
*Be honest. Smooth the reader’s way, anticipating difficulties and forestalling them. Aim for clarity, not pedantry; understanding, not
  fuss.
  
*Remove the irrelevant. Irrelevant assumptions, incorrect emphasis, or even the absence of correct emphasis can wreak havoc.
  
*Use words correctly. Think about and use with care the small words of common sense and intuitive logic, and the specifically mathematical
  words (technical terms) that can have a profound effect on
  mathematical meaning.
  
*Resist symbols. The best notation is no notation; whenever it is possible to avoid the use of a complicated alphabetic apparatus, avoid
  it.
  


I would like to add


  
*"If you work eight hours to save five minutes of the reader's time, you have saved over 80 man-hours for each 1000 readers, and your name will be deservedly blessed down the corridors of many mathematics buildings." p. 134
  

and emphasize that at least the former holds for every scientific writing.
A: As someone who is currently working on my first mathematical paper, I've found this guide from MIT to be very helpful. It covers both writing a clear and precise paper in general as well as the specific challenges presented by a mathematical paper. It's also fun to read! For example, the author likes to illustrate common mistakes within the text. One of my favorites is:

Don’t string adjectives together, especially if
  they are really nouns. Many high quality pure mathematics original research journal
  article sentences illustrate this problem.

A: There are some notes on Mathematical Writing from a course taught by Knuth. They are quite extensive; I've only read the first few pages and those were already quite helpful to me, but there are also notes from guest lectures by various people, e.g. Wilf and Halmos. 
A: You say you haven't published a paper yet.  Then perhaps this would be useful to you:  How to Write Your First Paper by Steven G. Krantz (Notices of the AMS, December 2007, pp. 1507-1511).
A: http://padic.mathstat.uottawa.ca/~mnevins/latex/sample.pdf, here is a good short and simple guide. other is the following: www2.kenyon.edu/Depts/Math/Aydin/.../Report.doc, which goes to the main aspects of the body of a math report.
Hope to be useful. Greetings.
