This may or may not hold anything for experts to learn, but I am new to boating, and found a real nice no-nonsense guide to seamanship online that I thought others might like to have a look at as well. It is certainly much more in-depth than anything I have found in other sources to date, and it's free to boot!
It's the Canadian Coast Guard "Search and Rescue - SAR Seamanship Reference Manual", and can be browsed online in HTML form, or downloaded as an Adobe Acrobat (PDF) file.
http://www.ccg-gcc.gc.ca/sar/nsm-msn/main_e.htm
The Table of Contents looks like:
Introduction
Chapter 1: Maritime SAR in Canada
Chapter 2: Human Factors
Chapter 3: Personal Safety
Chapter 4: Vessel Safety
Chapter 5: Seamanship and Terminology
Chapter 6: Navigation Safety
Chapter 7: Navigation
Chapter 8: Waves and Weather
Chapter 9: Boat Handling
Chapter 10: Towing
Chapter 11: SAR Operations
Chapter 12: Emergency Care and Transportation of Maritime Casualties
Search and Rescue Algorithms
Enjoy!
Barry
Nice Online Seamanship Reference 
