These really are a fantastic sight atm. There is an adult pair plus three chicks that have just fledged, so you have a very good chance of seeing something.
more details here
In the next month they will have to learn to fish for themselves, so that would be wonderful to see. Apparently they will head off for Africa during the first couple of weeks of September.
There's a steep-ish but short walk up to the first viewing area, and a longer but less steep one up to the second area where you can view the nest.
Lots of people there with all-terrain buggies and many young children.
At the viewing area there are lots of friendly and helpful staff (RSPB, Forestry Commission, and National Park staff). There are telescopes set up that you can use, and binoculars you can borrow.
There's a charge for the carpark, but no other obligatory charges. (A box to put donations in if you wish, and the opportunity to sign up for RSPB. Also back at the car park there's a cafe selling English Lakes Ice-cream, among other things, which is hard to resist!)