Beginning Flex: Creating a new Flex project in Flex Builder 3
While creating a new Flex project isn't hard, there are a lot of options displayed, and the beginning user might not know what they mean, or what is needed. This blog post will cover how to create a new Flex project so that you can jump straight into writing code.
When you reach the dialog box labeled "Create a Flex Project", the only required fields are Project name, Project location, and Application type. Name the project whatever you like, put the files wherever you like. Should you choose to create a Flex based AIR application at this time, you'd choose Desktop application instead of Web application. The Application server dropdown allows you to preconfigure connections to your server of choice directly from within your project. If you're using ColdFusion, this can all be configured on the server. The next box should just be left as "bin-debug". The final box allows you to link code libraries and other projects to your new project without having to duplicate them into the newly created directory.
After your project is created you'll see several directories and files. The only folder that you really need to worry about to begin with is the src directory. This is where all of your project files are stored (not counting external libraries of course). You can create any number of new folders and files inside this directory, and all of them will be available to your code. Once you've run your project the first time, the compiled SWF files can be found in the bin-debug folder.