Do not use the QuickTime H.264 codec. It is a terrible codec, with many problems (including gamma shifts, poor compression, and various stability issues).

To be clear, this is not a problem with QuickTime as a whole or with other H.264 codecs: just the specific QuickTime H.264 codec.

What exactly do you intend to do with this file? The answer to that question will dictate what export settings to choose, including codec and format.

See this:

"FAQ: What is the best format for rendering and exporting from After Effects?"

By the way, since you're new to After Effects, I very strongly recommend that you work your way through these materials:

"Getting started with After Effects"

Doing so will prevent a lot of frustration.

But what do you intend to do with those files that you're trying to fit onto a DVD?

Will you be uploading them to Vimeo?

Will you be showing them to a client for approval of colors? Timing? Quality of keying?

Will you be bringing them into another post-production tool for color keying? Adding titles?

Again, I recommend that you read/watch the items linked to from here:

"FAQ: What is the best format for rendering and exporting from After Effects?"

> So what i'd be looking for is the best way to render these scenes to a small filesize but keep the quality almost untouched.

There is no such thing. If you want "untouched" quality, you will have large files. Knowing exactly what you need these files for will help us to recommend the right codec and such to make the necessary tradeoff between quality and file size.

If you are intending to use the files in another post-production program (like Premiere Pro), you want to use lossless compression. These will not be small files.

Sorry, but that's a reality of working with video.

If this is a personal project and you don't care about the quality of the final result, then go ahead and try to make these intermediate files small. But in real projects, you absolutely must use lossless compression (and therefore large files) to go between post-production applications.

In the FAQ entry that I've already pointed you to a couple of times, there are suggestions for lossless compression types.

>  So if I use lossless compression for AE, put it into Premiere and then rendered it there...would it be the same filesize or bigger/smaller?

The size of the file out of Premiere Pro depends on what settings you choose when you export from Premiere Pro.

See this:

http://forums.adobe.com/thread/878590

The thing to keep in mind is that you never, never use lossy compression until you are ready to create your final files for distribution. For all intermediate stages, use lossless compression.

Again, unless you want to throw away quality at every step, you need to give up on the idea of using small files except for final delivery.

Yes.