There are several methods for determining the standard effects provided by Flex. Here are a few that come to mind:
1. See "Available Effects" in the documentation (livedocs.adobe.com/flex/201/html/behaviors_068_05.html). As with most of the Flex 2 Language Reference, the effects classes have example code included in their documentation.
2. Use the Adobe Flex 2 Component Explorer. This is my favorite method because clicking on the various effects allows you to see an example of the effect in action and example code for producing that example effect is shown. In the Component Explorer, look under "Effects, View States, and Transitions" and then under "Effects" to see the available effects.
3. Examine mx.effects package API documentation or mx.effects.effectClasses package documentation.
In addition to these standard Flex effects, custom effects can be created as described at livedocs.adobe.com/flex/2/docs/00001640.html .