<p>I'm interested in writing eclipse plugins where do I start? </p>

<p>What resources have helped you?</p>

<p>I'm looking for:<br>
  1. Tutorials<br>
  2. Sites devoted to plugin development<br>
  3. Books  </p>

You can find a good step by step detailed tutorial here:
http://www.eclipsepluginsite.com/
Other tutorials:
http://www.ibm.com/developerworks/opensource/library/os-eclipse-snippet/index.html?ca=dgr-lnxw16RichEclipse
http://www.vogella.de/articles/EclipsePlugIn/article.html
A decent book, that I've used is "
Eclipse: Building Commercial-Quality Plug-Ins
".