I do not have this ebook yet but it's good book to read. so, I share.

This book seeks to help developers and testers who are making the transition from testing traditional client/server, PC, and/or mainframe systems to testing rapidly changing Web sites and applications. This book explains the technologies that are typically used to build these Web sites/applications and suggests specific test cases and techniques that can be included in a Web site’s test plans.
 
The book provides test-plan strategies, each plan focusing on a single aspect of the Web site under test (WUT), e.g., usability, compatibility, performance, etc. The book illustrates the benefits of having these multiple test plans, and provides strategies for implementing them.
Checklists appear at the end of each section, which can be used as a set of candidate test cases for each test plan.
 
The chapters are as follows:
# Chapter 1 Introduction
# Chapter 2 Code Quality Assurance
# Chapter 3 Compatibility
# Chapter 4 Navigation
# Chapter 5 User Interaction
# Chapter 6 Usability and Accessibility
# Chapter 7 Performance
# Chapter 8 Scalability
# Chapter 9 Reliability and Availability
# Chapter 10 Emerging Technologies
#  Chapter 11 Post Implementations

You could find review from  http://www.stickyminds.com/books.asp?ObjectId=410&Function=DETAILBROWSE&ObjectType=BOOK#review