After you first launch Flash, you will be presented with a Welcome window. You are required to make a selection to begin using Flash, however you can check the box to prevent this window from opening again.

There are several options in the center column based on the type of project you wish to begin. For Flash projects, you will only want to select one of the two first choices. The biggest decision you have will be whether to create a project in ActionScript 2.0 or ActionScript 3.0.

ActionScript

ActionScript (AS) is a programming lanuage that Flash uses to create interactivity. Recently, Adobe updated the version of ActionScript to create many new features for advanced programmers. While advanced programmers have praised the new lanuage, it has become less user-friendly to beginners.

Since the two languages are incompatible — meaning projects created with ActionScript 2.0 cannot be opened in ActionScript 3.0 — Adobe has decided to keep its support for ActionScript 2.0 for the time being.

This beginning tutorial uses minimal ActionScript, so it doesn't matter which version you pick at this point. However, we will proceed by clicking ActionScript 3.0.

Workspace

After Flash launches, you should first set your workspace to the way you like it. In Flash CS4, several new workspace "presets" were created, offering traditional users a way to create environments they were more familiar with. Since we are writing this tutorial to cater to previous versions of Flash, we will use the "Classic" workspace.

Adobe Flash 8 or CS3 users should select Window --> Workspace --> Default
Adobe Flash CS4 users should click Window --> Workspace --> Classic

Let's take a look at the Flash CS4 workspace.

Timeline: At the top of the screen is the Timeline. It is important to note that the Timeline is a frame-based timeline, not time-based. This means each of the squares represents one-frame of time — similar to a film strip or a flip-book.

Tools: At the left of the screen are the tools. The one important thing to note here is that the black arrow tool, also known as the Selection Tool, is the primary tool to move objects around. The white arrow, known as the sub-selection tool, is used for a completely different purpose (manipulating vector graphics). You should always use the black arrow. In fact, you will only rarely use the white arrow tool.

Stage: In the middle is the white area known as the Stage. This is the main preview area where your content will be placed. Content here can change based on where you are at in the Timeline. Surrounding the white area is a gray area known as the pasteboard. You can place objects off-stage on the pasteboard, but they will not be visible viewers who visit your site. Keeping unused items in the pasteboard area will export with your final movie, possibly increasing the filesize, so it's not good practice to keep unused items in this area.

Palettes: On the right are several icons and boxes. These are all for controlling various settings for different features. You can click the icons to pull up extra windows, or drag windows around to attach them to other areas of your workspace.

Important - Expand the Library! 

In the Classic view of Flash CS4, the Library is contracted into an icon. Click on the center icon that looks like some books (see image above). You can click and drag this icon to the right so that it snaps to the properties window.

Library: The library is an important aspect of Flash. It is where all of the media that is a part of your project is stored. Any time you import media into your project, such as an image or an audio file, it will be stored in your library. Your library also acts as bin for "master copies" of media in your project. For example, let's say you have a photo in your project, and you replace the library copy of this photo (by right-clicking and selecting properties), it will automatically replace every instance of that photo throughout your whole project.

Property Inspector: Lastly is the properties window, also called the property inspector. This window will show you settings for various things in Flash. Most importantly, you should know that the properties window is a contextual window and will change based on what you click. So if you click in your Timeline, it will show you the settings for your Timeline. If you click on the Stage, it will display settings for your stage.

The properties window will display on the bottom of the screen in Flash 8 and CS3: