Dog training... PLEASE HELP!!!!!!!!!!?

I need help with my dog, he seems to be a mix between a lab and a poodle, so hes pretty big.he loves his crate and will go into it willingly and he goes in it by himself sometimes without us even having to give the command 'crate up'. but when we go to close the door and lock the door, he goes ballistic and barks like crazy and snaps at us and gets a wild look in his eyes. Its really quite scary. we have tried many things to get him to calm down but he will not stop. also, he barks all of the time just when people are driving by the house or walking past it and he goes crazy when someone is at the door. i really need help, any type of assistance will be helpful, thank you.