Drugs, Brains and Behavior by C. Robin Timmons & Leonard W. Hamilton (formerely published by Prentice Hall as Principles of Behavioral Pharmacology):
http://www.rci.rutgers.edu/~lwh/drugs/,
   
Psychopharmacological Concepts : http://www.rci.rutgers.edu/~lwh/drugs/chap03.htm, 

Clinical Pharmacology (Merck): http://www.merck.com/pubs/mmanual/section22/sec22.htm

Drug Information Database: http://pharminfo.com/drg_mnu.html, - http://pharminfo.com/drugdb/db_mnu.html,

Internet Drug Index: http://www.rxlist.com/,

The Children’s Hospital Handbook - http://www.nch.edu.au/prof/handbook/1993hb30.htm#E9E31,

 
Pharmacology - lookup info (indications - dosage, contraindications/precautions, drug interactions. adverse reactions,costs,product identifications, classification) - Drug Information from CP2000 , 

Psychopharmacology: http://www.fpnotebook.com/PSYCh12.htm,

Pharmacology Notebook: http://www.fpnotebook.com/PHA.htm,