Mine is well over a year old =S I did it myself on PSP7 and Animation Shop haha. I don't know if I still possess to skills to make another.
I'm sure there are loads of members willing to help you out in the arty section of the forums though. I recently got Photoshop, it looks really complicated =[
As for CS2 or CS3, I say: "If it ain't broke, why fix it?" My CS2 works fine, I see no real reason to upgrade.
As for making your own sigs.. Just check out tuts, get used to the program you are working with.. Don't be afraid to play around with it, and always ask people for their inputs, you pick up new tips and get better. Good Luck!