Welcome to the site, Alex!
Congrats on the bodhran for Christmas
Before applying water to the head of your drum I would say that it depends on how your drum currently sounds. If it doesn't sound 'tinny' you probably don't need to put water on it. But if it is tinny I would recommend spraying a little bit of water on it (best done with a spray bottle) and then giving it a quick rub with your hand, wiping the excess off with a dry cloth.
I would say that you're probably okay with wetting it a bit everytime you play is fine. A lot of players do that with the non-tuneables. I also play a non-tuneable and find that I have to do it once in a while. Mind you, with me being so busy with school I haven't had a lot of time to really play lately. But on occassion I'll take my Bessie down and play just to keep my hand in.
If you find that the drum head is getting really dry then you may want to treat the drum head with a bit of mink oil or aqueaous lanolin (usually available at shoe stores). Use only a little bit on a chamios or bit of flannel and work it into the top of the skin. You don't want to use too much because too much oil means you'll have an unplayable drum for quite a while. The nice thing is that you won't have to treat the skin very often because as you play the oil continues being spread and worked into the skin. I've had my bodhran for several years now and have only oiled it twice.
Have fun, and bang on!
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"To sin by silence when they should protest makes cowards of men." ~ A. Lincoln
"Age is no guarantee of maturity." ~ L. Blackwell
"A word to the wise isn't necessary, it's the stupid ones who need advice." ~ B. Cosby
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