I used Flash book, some years back and worked through exercises to learn the basics and then having picked up some basic principles learnt more as I went along by just looking things up each time I needed to achieve a certain thing, like you are saying, seeing other peoples work and playing about with it can help pick up new stuff.
I find this site useful for Flash templates, resources, tutorials and stuff
Flash Kit, A Flash Developer Resource for Macromedia Flash MX Tutorials SWF FLA images clipart Sounds WAVS Animations Help and Support
There are loads of things to download there and often come with tutorials as well to explain what is going on, thats useful as I dont know about you, but sometimes I find it not so easy to follow what another developer is doing if I just have the template. That site gives quite good explanations as well.