Camping......
I quite often stay at the site opposite the Old Dungeon Ghyll, just turn up and pay the warden in the mornin'. Wasdale head has a decent site & pub.... Failing that you could always try bowling up to the Woolpack Inn, Eskdale and see if you can camp on their land.
Youth Hostels.... Patterdale is a nice one. If you fancy walking in the Howgills, try Tebay youth hostel (if it's still a hostel) and say Hi to Dave & Pat from me.... BTW The Cross Keys is usually quite good for lock ins....
Enjoy....
M