First off, welcome to VB
When I decided to become vegan from vegetarian two years ago I called it my 'five year plan'.
For the first year I cut down on all visible dairy and learnt to read labels so that when I was ready I would already have a feel for which foods to avoid and which I could eat. I was concentrating more on raising my awareness of what I was eating than actually avoiding anything. No pressure!
Now my diet's sorted I'm concentrating on toiletries, and I'm finding it harder to read labels on those! I'm getting there slowly though.
As to why I went vegan? Well, I was vegetarian already out of concern for the treatment of animals and simply because I didn't want to eat them
I started researching the effects of milk on the lungs, because something in the combination of a fizzy drink and a cup of tea before bedtime was bringing me close to an asthma attack every night. I'd been eliminating things to try to figure out what was the problem.
While researching how to cut milk out of my diet (since I realised that was the major culprit) I came across a lot of vegan sites. I realised that the vegan lifestyle was entirely fitting with my ethical beliefs and I decided that I would eventually become vegan, it was just a matter of time.
I have an odd tip, but one that has consistently worked for me:
While transitioning, if you have a craving for something that you cannot ignore, then have some
I've done this with fish, cheeses, eggs, and other stuff. I've always found that it never tastes as good as I've built it up to be, and my resolve is strengthened because I can directly weigh the experience of eating the food against the price paid for it (death and suffering of an animal).
I've never had another craving for those foods that I've done this with. Instead of 'forbidden foods' that taste great, they now equate in my mind with disappointment.
And yes, Joanne Stepaniak is very inspiring! I love her compassionate, tolerant approach and it's something I aspire to. In case you haven't seen it, she has a nice website here http://www.vegsource.com/joanne/
Best of luck with your transition