Fellow Pagans, do you know if there is a tradition devoted to the Tuatha Dé Danann?

Not that I know of, but there's no reason you cannot belong to a tradition such as Gardnerian, Alexandrian or another and make your own focus of work be the Welsh stories and pantheon. The Tuatha de Danann are involved heavily in all Celtic Mythology, so I'd recommend looking at Irish, Scottish, and English mythology as well.

I have a book in my collection called "West Country Wicca - A journal of the Old Religion" written by Rhiannon Ryall. It's the closest thing to what you are looking for that I know. Here's the amazon link:

http://www.amazon.com/West-Country-Wicca-Journal-R...

Most Celtic Reconstructionists go with either one tradition or the either, not mixing and matching them buffet style. If you're an eclectic neopagan, presumptuosly equating yourself with all of paganism, just make it up.

Try either The Witches' Voice or The Celtic Connection (links below); either of them may know if you search their sites.

Other than that - I don't know either. (I know Wicca has one, but that's the religion I started my Pagan path with.)

I don't really know what Celtic pagans practice, but that's where i'd check first.

Of course, if you're familiar with the mythos, you can make the rest up yourself.

You need to accept Jesus as your savior and have a relationship with Him.