The following are links and books that I have found useful.

To begin with, the following books have helped with writting mysteries and suspense stories. You can get them at most book stores.
From the "Howdunit Series":
Cause of Death by Keith D. Wilson
Missing Persons by Fay Faron
Murder One
Body Trauma
Malicious Intent
Modus Operandi by Mauro V. Corvasce and Joseph Paglino
Police Procedural by Russell Bintliff
Private Eyes
Deadly Doses by Serita Deborah Stevens
Just the Facts, Ma'am by Greg Fallis
These books range from $13.99 to $16.99 and are wonderful. They each deal with different aspects of murder/arson and other crimes and the people who solve them.
There are some other wonderful books, visit your book store, especially Barnes and Noble. They have a whole section on better writting.
Onelist.com is where you can join the "Writewell" list where people put out questions and comments on stories they are working on.