Run and Gun is a Varicam owner. So is dazapper. Maybe Ed Scott, I forget.
Here's my two cents. If you are a stand-alone field shooter, know what settings your Varicam is in before you shoot with it. What frame rate is required? Is it in the film gamma or video rec mode? For most everday shoots, the video rec mode seems the better way to go. Understand before you go out how to get into the menus and how to manuever around them. Know what's important to you in them -- and what isn't.
along with your monitor, know how to get into and set up your zebras.
someone here will correct me if i'm wrong, but i'd error on the side of under exposing - they can always bring it up a bit - if you blow it out, its gone.
If you have a lot of VariCam work coming up, I recommend buying a Goodman's Guide. Worth every penny. It was written for the F, but most of it still applies to the H.