if you are talking how much a business charges a customer for an employee's site time, it can vary but here is what i know.
electrician: usually around $55/hr
plumber: between 45-60/hr (depending on level of experience)
carpenter: 35-45/hr (typ) i have seen some guys charge as much as 65/hr
HVAC: same as electrician 55/hr
most body shops i knkow charge a lot more than a construction company can for one guy, but everyone has their price.
as far as what those guys make an hour, i cannot really tell you. i know that a general laborer's pay for construction (union) is 28/hr. carpenter's union is 38 (i believe). outside of the union those guys make 12/hr and 18/hr. definately not a lucrative career choice.
state wages are a different beast, but carpenter's wages for state pay are 42/hr to start. I was making 52.50/hr on an air force base last summer, didnt want that job to end!!