Most would wear a cycling Jersey together with cycling shorts.

Cycling shorts prevent the rubbing of your inner thighs together while peddling (known as the chamois) and to be aerodynamic. http://cycling-review.com/clothing/bike-shorts/wearing-cycling-shorts/

No, you dont use underwear with padded cycling shorts lol! *still laughing* omg no. searouly? oh then no

There's a wide variety of sources out there for cycling shorts, so you should ensure that you're getting the best of the best. One of the stores with the best selection can be found at http://www.rei.com/search?cat=4500003_Cycle+Clothing&search=Cycling+Shorts

Benjamin Barnes