Shoes: hiking boots or closed toe shoes are highly recommended.
Pants: Pants or long shorts are preferred. The seats can get hot while sitting in the sun.
Shirt: long sleeve shirt recommended for the longer rides to keep you from getting sunburned. but in the hotter months short sleeve with sunblock will do just fine.
Jacket/sweater: you may want to bring a Jacket or sweater the weather can be unpredictable.
Dress in layers so you can change up what will keep you comfortable.