Pedals: Clipless pedals are required for bicycle tours. They will allow you to pedal in a higher gear at all times by pulling up on the pedals. SPD mini cleats are best for tours, since it will be easier for you to walk around. Make sure to get a pedal with some float, this allows your foot to move side to side, to minimize knee problems. MKS has an interesting removable pedal that can be used as a theft deterrent. However, any style Shimano, Crank Bros, MKS, or VP pedals with float should be fine. These companies have been producing pedals for decades, hence their product are very mature. Watch out for house brand pedals such as Forte, & Nashbar they are known to have problems.
Shoes: You will need to buy a set of shoes to accept SPD cleats. Do not buy shoes mailorder, unless you are certain of your size for the shoe brand. Shoes need to be tried on to see how they fit. Additionally don't buy high end carbon soled shoes, they are very stiff, fast, and uncomfortable. Get a shoe with a Nylon sole which will flex for comfort. I prefer multiple velcro straps on shoes, but you should select your own preference. Laces on cycling shoes are not normal anymore, so avoid those shoes.