Collision during editing?

As a newbie - one thing I find extremely frustrating is when trying to position objects on the landscape or against any kind of surface come to that, I am forever moving the camera through the mesh, and for me this makes positioning the camera and subsequently the objects take far to long. Can I enable collision whilst editing so that if I zoom to a piece of landscape I dont go flying through it then have to adjust back the other way, zoom back above again, and repeat, and reapeat until finally I get to a place where I have the perspective I want? Thanks for any help you can offer guys.