For me and my wife, we went "cold tofurky." And looking back, it was a great idea. Of course, we had to be quick about researching proper diet so that we did not hurt ourselves. But my wife switched primarily for the sake of the animals, and I switched primarily for health reasons (now we both sustain it for the animals first, and then health and environment). Basically, we both agree that making the instant change was the best route for us. It would have been too hard to convert slowly, as it would have given us license to "cheat" every now and then, making it harder to switch. That being said, it was also easy to switch quickly because we both immediately identified dead animal flesh with all the horrific pictures and videos we had seen of the abuse that goes on in the meat industry.
One of the hardest things to do is to figure out where you can eat...until you realize some easy tricks. For example, Papa Johns without meat or cheese is vegan. Asian can easily be vegan (see this article my wife wrote on the Examiner about Asian restaurants:
http://www.examiner.com/x-52338-Charlot ... gan-diningBasically, we have found it is actually pretty simple to be vegan, even in Charlotte, NC, where restaurants do not typically cater very well to vegan and vegetarian lifestyles.