I am just a new guy to this while 3d art things. I am using blender right now and just have finished 3 models that I would like to make a small movie with. I haven't gotten into animation yet with blender or any other software but am wondering....Can I make a movie completely with Blender or do I need to download some other software. or what do i need to do. this is all just a small animation project im doing for fun but maybe would like to turn into higher quality work.

so what is the best programs for making movies. I would really like to make some good quality animations and things with some characters I've created.

Blender can do some pretty high quality animations and renderings, see Project Orange as an example.

The AP said if you need to do more post processing, you'l probably need other softwares.

As far as the "what is the best program?" question, there is no real answer to that. The best way to get a great film is to have a great animator.