First off, you will need to take the Nitrox course to dive with Nitrox. You'll need the Nitrox "C" card to get a tank.
Second, once you are Nitrox certified you can rent Nitrox tanks, buy Nitrox tanks and get Nitrox fills.
You really don't need special gear except the tanks. They must be O2 cleaned. Your current gear should suffice (check with your manufacturer). One caveat to that is that it can't have Titanium. Titanium burns with high O2 gases.
As for dive computers, they make tracking your Nitrogen and O2 levels so much easier. But, it's good to know how to use all the necessary tables. You should know this in case your computer goes on the fritz.
Otherwise, Happy diving!