First order of business is the tires and tubes. Next is to replace the brake pads – which should be done annually, regardless if they seem worn or not. Most cables and housings run smoothly enough to last a few seasons, but run the bike through the gears and cycle the brakes to ensure there is no crud keeping them from operating correctly.
Check the quick releases before you ride, as you may have thrown a wheelset on without properly tightening it. Finally, if you have not been riding a lot, you might want to lower the saddle five to ten millimeters to make up for some lost flexibility. Crank it back up to full height in a month of riding, after your legs have relaxed back into fitness.