Performancebike.com sells a lot of jerseys, including their own, which aren't bad. They have sizing charts for each brand. I wear a medium Louis Garneau and a large Santini; I'm 5'8" and have a 38-39" chest.

Some jerseys, like the Santini, have a collar that may bother you. Some have a full zipper, some have a half or less. Most have 3 pockets in the back, some have zippered pockets.

Some jerseys, like Volers, come in Race and Club cuts. The Race is skintight while the Club is a bit fuller. You don't want a loose jersey that flaps in the breeze but if you are like me you don't want the skin-tight ones, either.

If you are overweight, check out the mountain bike jerseys; usually cut fuller and not meant to be tight.