I just bought my first AR (Olympic PCR-4) and it shoots like a dream, but while sighting it in I have encountered an odd problem with the rear sight.
starting at mechanical zero on both sights the rifle printed more than a foot low and to the right (on a 50 foot range).  I have no idea how usual that is, but I'm pretty sure that the windage adjustment is not normal since I had to move the rear sight all the way to the left to make it shoot right.

I'm not worried about the elevation since I still have enough space to play with, but I'm fairly sure that the windage should not be pushed left until it stops.

does anyone have any advice for me on how I could get my new baby shooting straight?

When your barrel was installed, the barrel twisted and the sight tower canted to the left.  The solution is to just pull the barrel and re-set the barrel with out canting the front sight.

The reason that your having to move the rear sight to the left, is the front sight is aiming left of impact and by moving the rear, your just overcoming the canted/off indexed(center line of barrel) front sight.

Hope this helps.