Reddit reviews The Gods of the Celts

Okay so:

Read our FAQ first if you haven't. This will help orient you to our site here.

Read through Seeking. While you already have an interest on a cultural background, it is useful to explore more information for someone getting into Pagan religious practice.

I really recommend picking up a copy of John Michael Greer's A World Full of Gods: An Inquiry Into Polytheism, where you can find it used cheaply. If you're coming from a non-polytheistic background it helps orient you towards that.

Now, the next question is: which Celtic religion? This is a lot more nuanced than people think. What I'm going to do is assume that you mean Gaelic/Irish Celtic, because that's what most people who aren't in relevant fields of study think of when they think of Celtic. Assuming you meant Irish, the following are useful sources that are all pretty standard and good:

• Tairis Gaelic polytheism site
  
  
• Gaol Naofa's site
  
  
• Mythic Ireland by Michael Dames
  
  
• The Year in Ireland by Kevin Danaher
  
  
• Celtic Goddesses by Miranda Green
  
  
• Gods of the Celts by Miranda Green
  
  
• Celtic Mythology by Proinsias MacCana
  
  All of these are pretty standard for initial inquiry.
  
  If I assumed wrong, and you're interested in the other two big Celtic traditions that are out there (Brythonic and Gaulish), I'll dig sources up for those, too.
  

I am currently (and slowly) reading Miranda Green's The Gods of the Celts. I picked up my copy at the library but you can find it on Amazon. It is pretty good so far.