Believe it or not there is a tremendous amount of information available covering AppleScript. The bulk of this information is located on the World Wide Web and the rest is composed of well written, but possibly hard to find, books.
Depending on what you need to do with AppleScript you may have no trouble finding answers to your questions, pre-made examples or complete solutions made using AppleScript.
Even with most programs being scriptable, you will find more general AppleScript guides and references instead of program-specific tutorials. Once you are familiar with AppleScript in general you can easily apply it to suit your needs regardless of program or task.
AppleScript on the Web
The largest site I have ever come across to date is the AppleScript Sourcebook web site <http://www.applescriptsourcebook.com/>. There is a lot of information on this one web site and it may take some time to digest it all, but you will most likely find something useful no matter who you are or what you are using AppleScript for. The whole site could possibly be condensed or sub-divided more to make the content more accessable, but once you go over it once or twice you shouldn't have too many problems.
Apple Computer Inc. offers its own AppleScript web site, finally, that is more basic than the AppleScript Sourcebook at <http://www.apple.com/applescript/>. Apple finally has provided a Beginner's Guide for AppleScript that can even be downloaded and installed into the Help system of Mac OS 8.5 and newer <http://www.apple.com/applescript/begin/pgs/begin_00.html>.
In a strange twist of the Internet the OSAX (Scripting Additions) list that should be featured on ScriptWeb.org is located on a completely different server at <http://www.scriptweb.com/temp/osaxen/>. Go figure.
If you want more technical detail on AppleScript there is the AppleScript Language Guide <http://developer.apple.com/techpubs/mac/AppleScriptLang/AppleScriptLang-2.html>. This reference is aimed more at those who want to know what AppleScript can do and how to do it. Previous experience with AppleScript would be a good idea before digging in to this web site.
AppleScript References in Print
There are several books that you can purchase that will provide basic through advanced AppleScript tutorials and references. It has been some time since most of these books were originally published so you might have trouble finding them at a local bookstore, but with a quick trip to Amazon.com you could place an order for any one with little hassles. Ordering a book is not necessarily a gurantee that you will get it however as its up to the publisher to produce more copies as demand warrants.
All of these web site cover general AppleScript topics. The biggest application-specific sites are focused around the Ircle IRC Chat client for the Mac OS and Email clients. Millions of people use AppleScripts to help them manage their overflowing email boxes and tens of thousands of people use Internet Relay Chat every day and many of them are using Ircle. Ircle is fully scriptable and there are dozens of custom AppleScripts that add to or enhance Ircle's features.
If you are using Claris Emailer you can go to either the Emailer 1.0 site <http://www.fogcity.com/em_utilities.html> or the Emailer 2.0 site <http://www.fogcity.com/em_utilities2.0.html> maintained by Fog City software, the original creators of Emailer. There are many many different scripts that perform a multitude of actions on your email or with Emailer. Emailer is one of the hard applications to script, I speak from experience, and having pre-made examples or solutions is a great help.
Two of the bigger How-To sites for scripting Ircle are Ircle Scripting Resources <http://www.pasoftware.com/isr/> and the AppleScript for Ircle Guide <http://members.aol.com/ratserv/>. Both sites are specific to the Ircle IRC client and include tutorials, guides, samples and other information covering AppleScript for Ircle.
I am sure that there are many more smaller/obscure web sites for specific applications, but Emailer and Ircle are the two largest representations of AppleScript for a particular program that I am aware of. If you dont use either, there are most likely resources available and a quick trip to your local Search engine should reveal them.
This article is by no means a definitive reference for AppleScript links on the Internet. All URLs are verified to be current at the time of writing only. If you have more to contribute contact the author of this article, not the webmaster of this site.