The 3D Studio Max Video Post was originally designed as a Video post-production utility inside 3D Studio (hence the name). Since then it has developed into the special effects application and output device. Be forewarned, however, through its evolution it has acquired any number of little "features" (read as: bugs) which can detract from its usefulness (they certainly detract from its ease-of-use). Let us begin.
Upon opening the video post you will see a row of somewhat ambiguous buttons on the top row, as well as a few buttons on the bottom of the window, similar to the Track View. The buttons on the bottom, just like the track view, are used to scale and zoom in on the video post. The buttons on the top are for creating view designations, image input events, image filters, and image output events. First, let's deal with the overall layout, which is fairly simple. On the left is a list of every video post event in the scene, arranged in the order in which they will be applied. If this is the first time you have opened the video post in a given scene this list will be blank. The larger field to the right designates for what period of time a given event will be applied. The default as of version 3 is, for some strange reason, 30 frames. Next is the view designation button, appearing as a small blue teapot. This is a required button for any scene which will employ the video post, as it tells the post what view to render and then apply effects to. The image input event can be used to draw in a image you have already rendered and apply filters to it. Bear in mind, however, that any filter which requires in-scene objects will not work, such as the lens flare effect and most ramifications of the glow effect. Third, the image filter button. This is the heart and soul of the video post. Here you can place glow effects, lens flares, blurs, even Photoshop filters. Note: effects are applied in the order in which they appear in the video post, they are not applied simultaneously. Not keeping this in mind can produce some unwanted results, so don't forget. Accidentally rendering the blur first, and then the lens flare gives you a very clear lens flare against a very blurry background. Which would look....awful. Bear this in mind. Fourth we come to the image output event button, which works much like the file output section of the rendering screen. You save the rendering as a movie (in an animation) or as a still screen. Finally, and this is important, using the render window to render your scene will not use the video post effects, only the effects in the Effects window in version 3. To execute video post effects, you have to use the Execute button, denoted by a little running man.