I suspect - but I'm by no means certain - that JasonC's last sentence may no longer be up to date following recent developments (last 2 or 3 weeks). This is in the wake of problems occurring on Casterton Fell earlier this autumn. (We have a project in one of the caves in lower Ease Gill which previously didn't have a permit system but as of last week now does - I don't know what the situation is further up valley though.)
Given that things are still a bit sensitive, if mark22gsiturbo1 hasn't done any of the many other fine caves in the Dales before, I can't help pondering on whether it might be preferable to go elsewhere on this visit to reduce the pressure on Casterton / Leck in particular? Unless of course you specifically wanted to do something in that area, in which case talk to the relevant CNCC officer a.s.a.p. assuming your club is a CNCC member. Even if your club isn't a member it's well worth a chat with a CNCC officer if you are looking at trying to go caving on Casterton or Leck. The CNCC is all about helping people get access, not creating obstacles to going caving as some folk occasionally seem to think. (In fact the CNCC website has loads of help and information about access right across the Dales.)
Just to add to others' comments above - the Ingleborough Estate is very supportive of cavers wanting to go up to the GG area potholes (thanks to the landowner Dr.John Farrer, who is an honorary member of at least three northern caving clubs!) - but they do expect to issue permits formally. The lady in the estate office in Clapham (which is only open midweek mornings incidentally, in case you're thinking of calling in person to ask) is generally very helpful. I think they also require anyone going caving to have BCA insurance cover though, so bear that in mind if anyone in your group isn't a club member covered by the scheme.
The above is genuinely offered as help rather than hindrance.
Sell Gill Holes near Horton in Ribblesdale is an interesting trip including nice pitches and a large chamber, with no great difficulty. The entrance is right next to a public footpath and I'm pretty sure there is no need to ask permission to descend. The Dry Entrance is doable in just about any weather conditions. The Wet Entrance is a flooder though, as is the extension beyond the old downstream sump (down the streamway from the Main Chamber) - so definitely avoid these areas unless the weather's guaranteed settled.
I hope you have a brilliant weekend, wherever you end up!