Below are some book searches for topics I find interesting

• Drupal is a powerful and very modular web development framework used for building websites ranging from simple brochure websites to complex, database driven sites (community sites, social sites, etc.).
   
• Search Engine Optimization or just SEO is used to help make a web page or site more visible in the major search engines (Google, Bing, Yahoo).
   
• Web Analytics can be used as a feedback mechanism to help refine the process of SEO and is the statistics behine the usage of a website.
   
• PHP is a very popular open source web programming language with syntax similar to C++ and is what Drupal runs on.
   
• MySQL is also an open source, popular database application used to power many websites on the internet.
   
• Linux is a popular operating system used on many internet servers and is also open source.
   
• Shell Programming is generally a method used to create automation in the world of linux.
   
• Cloud Computing is a new paradigm in the world of performance computing
   
• Marketing - interestingly, online marketing is simply a subset of this
   
• Mac Computers - I just think Macs are great :)

Here are some individual books that are useful

Pro Drupal Development covers drupal 6 and is an excellent guide for developers

Module development is an essential ability for drupal developers 

Semantic Web for Dummies is a nice future view of what the "meaningful" web will look like

Solr is an open source, enterprise level search engine and is very cool

Some other cool stuff that I don't have enough time for anymore

• Games
• Surfing
• Running
• Guitar playing