A good way to get a base knowledge of the area is to enter an event like the Wild Boar Chase.
Alternatively, post on here (STW) a week or so before a trip here (FoD) and ask if anyone can show you around, or go through FoDMTBGuides or Pedalabikeaway and pay for a guide (not a lot of cost if there’s a group of you).
It is a frustrating area because there is so much riding so close to where you might be at any given time! I often see people riding along the road towards some of the better known singletrack and missing out some equally good but little known links. I’ve been fortunate enough to have introduced a lot of riders to trails in the area but these days I just pootle along somewhat more slowly than most youngsters want to ride 😉