Recommended reading: HowToReadSmalltalk? http://www.speakeasy.org/~podenski/stug/reading-smalltalk.pdf
[One wikizen's experience:]
As I got interested in DesignPatterns and ExtremeProgramming, I constantly saw references to the Smalltalk language and how well it fitted these purposes, as well as being a pure ObjectOriented programming language. On googling Web sites and news postings on the subject, I realized I had a narrow programming language experience in that I only knew statically typed languages (Java and C#). Upon downloading VisualWorksSmalltalk 7 (Non-Commercial), and joining the IRC chat room #smalltalk, I was ready to begin my journey.
I have found that the VisualWorks IDE is excellent and can't wait to start developing something in it. This will probably be software for my brother's business. I'll do this for free and use XP to drive it. Meanwhile I have a few books to finish - RefactoringImprovingTheDesignOfExistingCode and ExtremeProgrammingInstalled. -- MarkMarsella
See also LearningSqueak