W3Schools.com

W3 Schools--a great place to get started with Web-based (HTML, XHTML, XML, WAB, etc.) as well as some SQL/Database tutorials and the like.

WebTeacher.com

Similar to the above, W3Schools, but covers the following areas of interest: WebDatabase, Javascript, CGI (Perl and CGI) as well as offering cpt, CGI (Perl and CGI) as well as offering consulting services. They also offer the Web Data product, which purports to be the first EASY database for the web as a FREE download. (I haven't installed it yet, so I'm not sure if it's "crippleware", a trial version or just a Really Good Thing.

Sun's Java Tutorial (May just be an intro)

Get it from the source. If this is not a complete on-line Java tutorial, at least it's a good start, and there are some handy pointers and links, too.

University of Tennessee Astronomy 162:Stars, Galaxies, and Cosmology Lecture Index

The University of Tennessee's Astronomy 162 class focuses on the entire universe beyond our solar system.