I don't use Camtasia - I use ScreenFlow. But I have a buddy who uses Camtasia on Windows, and loves it.
Awesome idea about the screencasts. I've had my woodworking YouTube channel up and running for a year or so, and I just passed 1,000,000 views last month. That's total views for all my videos. I still can't believe it!
I don't know your experience level with this kind of stuff - perhaps you know more about YouTube tutorials than I do, but if not, I'd be happy to be a sounding board for you. (I've done software tutorials too.)
Hit me up with a PM if you're interested, and we can trade email address. And if you're not interested, you won't hurt my feelings at all. Seriously, I'm easy.