Make sure you rinse off the old live rock really well, especially if you did not when you stored it. There can be a whole lot of crud left in the crevices of the rock.
I personally would go out and get a brute trashcan, fill it with dechlorinated water/RO water and a heater. Toss in the rock you want to use and let it soak for a day. Then toss in a powerhead and try and get any crud left on the rock off. After you get that crud off, dump out the water.
Fill up the bucket again, this time with salt water. Leave the powerhead in and add your base rock. Then, toss in some choice pieces from your LFS. Lighting the rock will just encourage an algae bloom. Leave it alone for a month or two- and you should have plenty of bacteria on your now cycled rock.
You could get fancy and put in some eggcrate held up by PVC, and then place a sand bed underneath to get some live sand started as well.