1. Get a set of strobes, an off camera flash, and bounce umbrellas.
2. Photoshop, plain and simple. Also, for headshots, try Portrait Professional.
Keep in mind that too much editing and people don't look flawless; they look like plastic and unreal so keep it simple.
If you want to do professional photos that will make them want to come back to you for pictures later on, use something big and black, as you stated, but DON'T go cheap. You can buy a large roll of paper at your local photo store, but keep in mind that any poses which could cause the dancers to...
I want my Gmail signature to have, well, my signature in it. Is there a way for me to upload it or store it on the server so that I can use it every time I send an email? It is in JPEG format right now but I use Photoshop so I can change it to basically any file format needed.