Learning new stuff: Unity

Two friends of mine, both game developers, swear by Unity.  Unity is a game engine and authoring environment that's designed to be accessible to indie game developers.  Now that it's free, I decided to give it a whirl, and I am impressed.  It's a deep tool, and I've only scratched the surface with the first tutorial, but so far, wow!  I love the visual approach that they've taken.  You put enemies in the scene, drop some scripts on them that define their behaviors, and boom, they're off and chasing you.  Here's a screen shot of the tutorial project.



There are two things I haven't quite figured out yet.

  1. How to place objects efficiently.  My objects end up floating off in space, then I need to go retrieve them and painstakingly bring them back.  I've started clicking on nearby objects, getting their coordinates, and copy-pasting them.  Anyone know a better way?
  2. How to track down errors.  My tutorial project had a bunch of errors I couldn't figure out.  Unity points me to the offending objects, but how do I know what's wrong?