Druids are still around today, but as a highly recronstructed path.
Myself, I study Druidism, allthough under traditional practices, I have to study for at least another three years.
One piece of advice is to use Oak for the staff, as it is sacred. Other than runes and other symbols, I can't give too much advice, as it is encouraged to do our own thing, and doing something just because someone else does (especially when it comes to decorating ritual tools, robes, etc.) is greatly frowned upon, and could be considered "sin."
If you want, PM me with you email address and I can send you files with various symbols and what they mean. And please be specific about what aspect of Druids you want this staff to be themed around.
Oh, and if you stumble upon anything that refers to an "ancient Druid text," disregard anything it says about Druids, as it was forbidden in Druid law to write down anything that partained to the teachings or ways. As I mentioned, what we have today is highly reconstructed.