theolderflyer,
I think the instructions in the link posted by 1800ed are very clear:
Visiting aircraft should be aware that the glider circuit is to the south of the concrete runway, and will either be 30 Left or 12 Right as appropriate. Overhead or dead side joins are therefore not permitted. Power traffic should use the North side of the airfield for circuits, these being 30 Right or 12 Left as appropriate.
and
Visiting aircraft are advised to join either at 1500 feet on the runway centre line (QDM) or down wind on the North side.
Flying down the centre of the runway at 1500' has the advantage of being able to see what's going on on the ground and checking the windsock and signal square.
I went there a couple of years ago. A very nice airfield and you have the advantage of telling your non-aviating friends that you made an "overseas" trip.
