Request for help with particles - Making Dust

Hello Blender Community,

I am working on a project that requires snow dust (Example) and I’ve had experience with particles, just not to the extent that I would like in Blender 2.5. So these are the task at hand, and I would be grateful for any help or tutorial links you can provide.

1: Render particles as dust/points
2: Random opacity for the particles
3: As the particles get closer to the end of their lifetime, I think they would become more

Realism and believability is my goal so anything else that might improve the results, feel free to mention. Thank you for your time.

PS: Is animation the correct support forum for particle, smoke, etc… related questions?