Howdunit: Police Procedures and Investigation: A Guide for Writers

This book is a nice informational book put together by a former detective. You can check it out on Amazon.

Here's the blurb from Amazon:
"
Not everything you see on your favorite crime show is accurate. In fact, a lot of it is flat out wrong. Police Procedure & Investigation helps you get your facts straight about the inner workings of law enforcement.
With
a career in law enforcement that spanned nearly two decades, author Lee
Lofland is a nationally acclaimed expert on police procedures and crime
scene investigations who consults regularly with best-selling authors
and television producers. Now you can benefit from his years of
experience with Police Procedure & Investigation.
This comprehensive resource includes:

• More
  than 80 photographs, illustrations, and charts showing everything from
  defensive moves used by officers to prison cells and autopsies
  
• Detailed
  information on officer training, tools of the trade, drug busts, con
  air procedures, crime scene investigation techniques, and more
  
• First-person
  details from the author about his experiences as a detective, including
  accounts of arrests, death penalty executions, and criminal encounters
  

Police Procedure & Investigation is the next best thing to having a police detective personally assigned to your book!"

I personally really like this book. It's put together really well. It explains procedures, jail time, types of prisons, types of police divisions, etc. If you want a book for some basic police information, this one is a good one.