Have a look at their website if you haven't already seen it: http://www.fleadhnua.com/
I have been every year for the past 8 years or so (apart from the foot and mouth year)and always enjoy it although I think it's not as busy as it used to be. It does not have as many really excellent sessions as you would find at Miltown or at the November trad weekend in Ennis (although there are some), but it is really welcoming and accessible for newcomers. It was my first festival in Ireland when I was just getting into the session scene and it was ideal for that.
There will be plenty of bodhrans about - it seems to be a rule that you can't have a session in the front bar of the Old Ground without at least four! - and you will probably find a session where you will be able to play if you are prepared to take turns with others. Hope you enjoy it!