Was there a few years ago - there's a pretty good museum, and a gun or two still emplaced. Well worth a visit, as is the whole area. Not quite sure what kind of gen you're after... bibliography? Photos? For the first, 'By Air To Battle' is a good place to start.
Loads, however i refer you to the Battleground book Pegasus bridge/merville battery by carl shilleto, however as i dont know what your after and im not going to write out 20 pages, maybe it would be better to ask what do you want to know.
One problem with Merville Battery and Hillman, the other well known preserved battery in the British Area, is that neither are shining advertisments for the effectiveness of aerial bombardment!
You might find the OR study of the effectiveness of bombing on ground targets of some use. You can find them in "Montgomery's Scientists: Operational Research in Northwest Europe: The Work of No. 2 Operational Research Section with 21 Army Group, June 1944 to July 1945."