W3Schools.com

W3Schools.com is a collection of very well written tutorials covering the basics of web development. The tutorials are excellent as quick start tutorials, with short and clear explanations. They include simple examples that can be modified and tested on the tutorial website. The reference pages of W3Schools are also very handy.

Tutorials Point

Tutorials Point is a collection of tutorials similar to W3Schools in terms of format. However, the list of tutorials available from Tutorials Point is different. It is worth to check both websites when looking for a quick start tutorial.

RoseIndia

RoseIndia includes a large collection of tutorials covering Java related technologies, web development technologies, frameworks, and other technologies and products. Most of its tutorials can be considered quite thorough and include concrete examples.

Tutorialized

Tutorialized is a searchable directory of tutorials and articles written and submitted by various organizations and individuals. It has a very comprehensive list of categories and a substantial number of tutorials in most categories.

IBM Redbooks

IBM Redbooks are developed and published by the IBM International Technical Support Organization (ITSO). They are how-to technical manuals written by developers for developers. Although IBM Redbooks serve mainly as tutorials and guides for specific IBM products and projects, they also contain a lot of generic material on technologies and design strategies that can be useful for developers. All Redbooks can be downloaded as free PDF documents. Printed versions can be purchased from IBM.

Laliluna

Laliluna includes numerous tutorials and articles covering Hibernate, Java Persistence, EJB 2, EJB 3, Spring, Struts, JSF, JRuby, Groovy and other dynamic languages. The tutorials contain complete working examples with source code.

Certification Study Guides

Certification Study Guides is a collection of study guides for all Java technology certifications and certain WSAD/RAD certifications from IBM.

DevX.com

DevX.com is an excellent searchable source of technical articles for developers. The articles contain good examples with source code.

Dev Shed

Dev Shed is a searchable source of technical articles and tutorials covering web development technologies.

JavaWorld

JavaWorld is a good searchable source of interesting articles for Java developers.

The Java Specialists' Newsletter

The Java Specialists' Newsletter is a good source of interesting articles and code examples for Java developers.

TheServerSide.com

TheServerSide.com is an online community for enterprise Java architects and developers, providing daily news, tech talks (webcast presentations and interviews with key industry figures), articles, discussion forums, and more.

The Java Tutorial

The Java Tutorial is a collection of practical guides for Java programmers. They include hundreds of complete, working examples and are organized as trails containing groups of related lessons. The Really Big Index is a very useful link for navigating through the tutorial.

The Java EE 5 Tutorial

The Java EE 5 Tutorial is the official tutorial covering all the technologies of the Java EE platform. It includes complete working examples with source code. The tutorial can be viewed as an html document or as a PDF document.

Java Generics FAQs

Java Generics FAQs is a monumental e-book on the subject of Java Generics written by Angelika Langer. It can be viewed as an html document or as a PDF document (513 pages).

Java SE Desktop Articles

Java SE Desktop Articles include a large collection of well written articles with lots of good code examples.

Eclipse Video Tutorial

Eclipse Video Tutorial is an excellent video tutorial that covers the basic features of Eclipse.

Refcardz

Refcardz is a large collection of quick reference cards.

Java Toolbox

Java Toolbox is a searchable list of Java development tools grouped in about 50 categories.

Open Source Software in Java

Open Source Software in Java is a searchable list of open source projects (software products developed with Java technologies and/or development tools for Java technologies).