You can put any pedals on any bike. HOWEVER, because of their size, shape and screw hole configuration you cannot mount Look cleats on mtb shoes. You could put them on road shoes and everything would work just fine. As Velocipedio points out, though, walking on Look cleats mounted on road shoes is clumsy and you have ZERO traction. As long as you ride only on roads you would be no worse off than any roadie using Looks, but if you think you will be doing any off road, Look cleats on road shoes is completely unworkable, IMHO.

Want some good pedals? Try Crank Brothers Egg Beaters. They are slick. Click in on any of 4 sides so you don't even have to THINK about which side is up. Which is very good for the slow-witted like me. I'm using them on road bikes. The cleats are about like SPD cleats, designed for MTB shoes.
Regards,
Raymond