How would I setup pycharm to recognize import arcpy? I'd like to use pycharm to develop and debug geoprocessing tool.
You can do this in the project Structure setting. Just add it as an sdk and it should work. I use intelliJ but pycharm should be the same.
Add this (Use your path) for the sdk path C:\Python26\ArcGIS10.0\python.exe
Give it a name and you should be good. Adding it as a global sdk you should be done and get the code completion.
theJones is correct, close all your projects and go to the program settings and search for Python Interpreters. Then select C:\Python26\ArcGIS10.0\python.exe and it should automatically add arcpy for you.