- download and set up the Flex 3 SDK, make sure the bin/ directory is on your path
- make a directory for your project
- in your projects directory make src/ and bin/ directories
- copy the flex-config.xml from the flex SDK's frameworks directory into the root of your project
- edit the flex-config.xml in your project, prepending ${flexlib}/ to all the libs/ paths and before the path references to manifest.xml and locale/
- edit the flex-config.xml in your project, uncommenting the source-path element and setting its path-element element to src
- create a compile file in the root of your project with the following content:
Make this file executable.
- Run the compile script to compile the project. The compiled swf will go to the bin/ directory and can be opened with your browser.
Here is a link to a zipped up version of a project where all the previously described steps have already been done for you (other than setting up the Flex 3 SDK of course).
This information primarily came from Simple Blog.
UPDATE: To use the trial data visualization components you need to copy several files over from a user that has installed flex builder. The instructions on which files and where they need to be placed in your sdk directory can be found here.
UPDATE UPDATE: The good people at Adobe have now made the data visualization components available as a separate download. You can find it here. You can download this archive and unzip it into your sdk and you will be good to go with the data visualization components - you won't need to download flex builder.