I built a bunch off these once, but using LTSP (the Linux Terminal Server Project) and network booting. If you can boot off CD or USB key it should be even easier - I'd be surprised if there wasn't a Ubuntu remix for this.
I found one version out there that was almost perfect, the fault settings worked great, just needed to add home page lock, wireless user/pass, and default homepage. The problem was the lack of clarity of how to setup the user parameters. =(
I will look into Ubuntu.
Lacking experience outside of just OS installation, Linux is a bit cryptic for me.
I taking on a personal project which requires a basic kiosk system
Try Xpud. It's about 50MB and runs great, fast load, enable your wireless and ethernet drivers and it has built in firefox browser. You can download additional packages with office or whatever you want.
You can boot from CD or live USB, even install it on your desktop as a instant on option.
Sure Ubuntu is a nice option, running from HD provides a very fast boot nowadays but Xpud is still the winner against all (with gui). Other than that, try tinycore, from Simple Linux. Good luck.