Save as .mov. Mostly go by the youtube settings to save, especially for the web.
Half of the other thing is just knowing how to animate. Add more frames or less frame, do the squishes and squashes, etc. I recomend the Animated survival Guide by Richard Williams which explains alot of this.
Via if you would get a job at pixar, an excerpt of pixar: What do you look for in Animators? One of the most common questions Pixar receives nowadays is, “How can I become an Animator at Pixar?” There’s really no good answer that’s both short and useful, so we’ve put together some information tohopefully provide guidance for people who dream of being involved in Pixar's animation process. Pixar places the technology of computer graphics firmly at the service of the art of animation, not the other way around. This priority is expressed clearly in Pixar’s production process, in which the Animators specialize in animation, with virtually all technical concerns handled by Technical Directors. The implication of this structure and this value system is what Pixar looks for first and foremost in Animators— we want you to be able to bring the character to life, independent of medium. Computer-graphic technical prowess is of course important, but the emphasis is not as strong within the Animation Department.
The reality is that computer graphic animators have no advantage over pen-and-ink animators, clay animators, stop-motion animators, etc. So while it’s preferable for someone to have 3D knowledge, it’s not paramount. In fact, three-quarters of the Animators on Toy Story were new to computers when hired. A common question is, “What software should I learn?” The answer is implied by the above: “Software doesn’t matter; learning to animate matters.” Still, you might expect that learning the software that Pixar uses would give you a leg up. However, even this isn’t true: Pixar uses its own proprietary software. Your knowledge of basic animation fundamentals is the foundation for your computer training, not the other way around.
Or read the faqs on this site. There is more about how to animate: [link]
I've tried .avi, I've tried .mov and I've tried .mp4. I seem to get the best quality from using .mp4, and for some reason, whenever I try to export it as a .mov, it tells me that the version of quicktime that I am using is not compatible with this version of Flash. :C
Flash animations are usually done in .swf when used for web content and uploading. This is the type that has the best quality because everything is still vectored. What are you planning on using the animation for?