That's an easy one. I recommend starting from Government Camp//Barlow Pass, or further up from Timberline Lodge. Hike north on the PCT around the west side of Mt. Hood and downhill. Go all the way to Cascade Locks. Get some more food, some beer at the PCT tavern and hostel (hostel not open i don't think). Then walk a couple miles west to the Eagle Creek trailhead. Hike up and south on that. It's spectacular. Really the whole route so far is, and it continues. When the Eagle Creek hooks back up with the PCT, retrace your steps on the PCT. If you are ahead of schedule and feel good, take the Timberline Trail around the other side of Mt. Hood (the east side), although be forewarned there's a large wash out at Eliot Creek that requires going above and onto the glacier a mile or so. No worries...if this looks too sketchy, you can always backtrack a half day to the PCT again, and it's so beautiful you won't have regrets. Whether your return is east or west of the mountain, either way you end up back at Timberline Lodge and then Government Camp.
I don't have mileages, but i'd estimate that the LONG way around, i.e. starting from Government Camp and returning east around Hood would total you about 70 miles. The SHORT way, starting at Timberline Lodge and backtracking around the west side on your return would total you about 50 miles.
Also keep in mind Timberline Lodge has a good breakfast buffet.