Welcome to the Squeak community!
When joining an open source project it can sometimes be hard to find out all the hows, whys and whats. Every project has its own culture and peculiar ways, and Squeak sure isn't an exception. :)
The Squeak community is very diverse, we have both legendary oldtimers who were involved in developing the very first Smalltalk back in the late 1970s and young newbies that just recently discovered Smalltalk. We have people from all over the world, and we have both low and high level developers and even some pure end users. Unfortunately we don't have many females, but we are hoping that will eventually change. :)
This diversity is something we value highly and we also value our friendly and respectful atmosphere that may actually be a result of it. Remember, everyone is a beginner at first and there are no dumb questions, in fact - many of our best discussions have been spurred by questions from beginners. We do not look kindly on flaming or disrespectful language, such behavior which you might get away with in other Internet communities will not make you look cool here.
The heart of the Squeak community is the squeak-dev mailing-list. For a long time that was the only list we had and we used it for everything and any subject. While this made things simple, it also flooded a lot of inboxes and made it hard to target specific people and sub projects.
Lately we have created additional lists for specific areas/projects and that has reduced the traffic on squeak-dev quite a bit, but squeak-dev is still the main forum when important decisions are to be discussed or for general questions and answers. Join it, it is for gurus and newbies alike!
Another important resource is the Squeak Swiki. Swiki is a wiki implemented in Squeak, and one of the largest Swikis running is the one about Squeak itself - the Squeak Swiki. It has almost 6000 pages with tons of information, but since it is a wiki it can of course be a bit "organic" in nature and daunting at times. It is the place where you find the most answers about Squeak and it is also a very good place to share advice or other information about Squeak. A common practice over the years has been to create a personal page on that Swiki about yourself, but these days we have a different infrastructure to keep track of ourselves - SqueakMap.
SqueakMap is a central catalog which keeps track of Squeak developers and the packages we share, thus SqueakMap is a bit like Perl's CPAN, but aiming to keep track of "everything Squeak" and not just packages.
Today (january 2006) over 370 developers and more than 600 packages are registered in SqueakMap and the growth has been more or less linear over a few years. All those packages can be installed from within Squeak with a single mouse click using a tool called the "SqueakMap Package Loader".
A good thing to do as a Squeak developer is to register your account in SqueakMap so that you can claim your unique "developer initials" - typically a short combination of letters that is used as a marker in any code you write. Lately some people have used their name, perhaps in "CamelCase" like say JoeSchmoe, and others have traditionally used much shorter names like di. This registry of developers may also be used for other community mechanisms in the future. Registering is easy and painless but we request you use your real name.
Another nice place :) where you should register an account is on SqP, commonly referred to as "Squeak People". SqP is a website that resembles advogato.org for us Squeakers, there you will find articles, diaries and above all a very interesting "trust metric" system in which you gradually can build up a trust from the community. SqP offers RSS feeds and an interesting view over ongoing projects and their users.
Finally, we also have an IRC chat channel called #squeak on irc.freenode.net. Go there and hang out with other Squeakers and get help or just make some friends. Typically there are 20-30 people online around the clock. You can even use IRCe an IRC client written in Squeak.