An all-encompassing (or nigh-all-encompassing, anyway) Web resource is Adobe Community Help. This service makes use of the Google Custom Search Engine (CSE) service to narrow the World Wide Web down to the sites that are most relevant to Adobe's customers. A large number of blogs and community sites are included in the search, so you can use this service to search across all relevant resources at once. Adobe Community Help is still in beta, so be sure to use the feedback link to tell us what you think after you've given it a spin.
Adobe provides documentation resources for After Effects on the Adobe website. Help is available in PDF and HTML formats. You can (and should!) leave comments on the HTML LiveDocs pages.
To make a feature request or file a bug report, fill out the feature request and bug report form on the Adobe website.
The Adobe After Effects User-to-User Forum is a great place to ask questions about After Effects and have them answered by other After Effects users.
You can subscribe to RSS feeds from Adobe Technical Support so that you can get notification of issues and workarounds related to After Effects (or other Adobe products).
For information on plug-ins available for After Effects, visit the plug-in page on the Adobe website.
Adobe provides resources for scripting and plug-in creation on the After Effects Developer Center portion of the Adobe website. The Video Technology Center portion of the Developer Center site has lots of information about the Adobe digital video and audio applications.
To exchange scripts, projects, and other useful items with other After Effects users, visit the Adobe After Effects Exchange.
Michael Coleman, After Effects product manager, provides news and notes about After Effects on his Keyframes blog.
A good place to ask questions about After Effects, especially with regard to integration with 3D applications, is the Mograph forum.
The ProVideo Coalition (PVC) website contains articles and blogs on topics of interest to professionals in the video industry. In addition to articles by Chris and Trish Meyer, the PVC website includes articles by Mark Christiansen, Frank Capria, Jim Feeley, Adam Wilt, Mark Curtis, and Scott Gentry.
The Toolfarm website provides forums, tutorials, and other resources related to After Effects and other Adobe products. The AE Freemart website is a division of Toolfarm that provides free tutorials about After Effects.
The AE Enhancers forum provides example scripts and useful information about scripting (as well as expressions and animation presets) in After Effects.
Jonas Hummelstrand provides tutorials, troubleshooting tips, and insights about After Effects and motion graphics in general on his General Specialist website.
Trish and Chris Meyer provide instructional resources for After Effects in many places, including their CyberMotion website.
Lutz Albrecht provides a list of After Effects error codes and some possible solutions on his Mylenium website.
John Dickinson provides tutorials and other resources for After Effects and related software on his Motionworks website.
Alan Shisko provides insights and tips about motion graphics on his Motion Graphics 'n Such blog.
Harry Frank provides tutorials on all areas of After Effects, with an emphasis on expressions and use of third-party plug-ins on his graymachine website.
Andrew Kramer provides tutorials and training on his Video Copilot website.
Dan Ebberts provides scripting tutorials and useful scripts on the scripting portion of his Motionscript website. Dan also provides an excellent collection of example expressions and tutorials for learning how to work with expressions on the expressions portion of his Motionscript website.
Lloyd Alvarez provides a collection of useful scripts on his After Effects Scripts website.
Jeff Almasol provides a collection of useful scripts on his redefinery website.
Ole Sturm maintains the Xscriptorium website, where users can upload and download scripts, expressions, animation presets, and example projects.
Stu Maschwitz provides insights and tips about After Effects and video, visual effects, and compositing in general on his ProLost blog.
Dean Velez provides many sample projects (some free) and other useful things on his Motion Graphics Lab website.
The Creative COW website provides several resources for After Effects users. Many of these resources feature Aharon Rabinowitz:
The Layers Magazine website provides articles and tutorials about After Effects and other Adobe creative products.
David Van Brink provides tips, insights, and downloadable utilities for After Effects and other digital video software on his Omino website.
Colin Braley provides tutorials, mostly about expressions, on his website.
Rich Young maintains a list of After Effects resources on his AE Portal News blog.
Rick Gerard provides tips and tricks on his AE Tips and Tricks website.
David Torno provides tips and tutorials about visual effects and compositing on his AE I Owe You blog.
Jim Tierney of Digital Anarchy writes about After Effects and related stuff on his Anarchy Jim blog.
Jerzy Drozda, Jr. (Maltaannon) provides After Effects tutorials on his website.
Dale Bradshaw provides a lot of clever scripts and hacks on his Creative Workflow Hacks website.
Richard Harrington has many facets to his web presence, and they overlap quite a lot. I find a lot of things that I like on the Photoshop for Video and Raster|Vector websites.
Sean Kennedy provides several video tutorials, including some very good ones about rotoscoping and motion tracking, on the SimplyCG website. They're all linked to from his website.
Ayato Fuji provides tutorials on his ayato@web website. Some of the tutorials are a little out of date, but the material is still strong, especially for learning to use some of the Trapcode plug-ins.
Ko Maruyama, Stephen Schleicher, and Brian Maffitt are among the people who post about After Effects on the DMN After Effects Channel.