The edge-pro is widely considered the pinnacle for knife sharpening among knife knuts.
The easiests to use is with very good results is generally thought to the Spyderco Tri-angle Sharpmaker.
I personally use the sharpmaker. Two grits but four cutting actions, different angles for setting up as a crock stick sharpening system and slots for use as a bench stone. Also works well for hand use as a file. Includes slots for sharpening points as on an awl. Will even sharpen vegetable peelers.
The Norton stones are nice. I think the Sharpmaker is superior.
The sharpening FAQ
is a good place to learn more.