@sleepvines Good question, it can be pretty hard to find things especially when they're scattered about.
First I'll give general advice and then I'll mention some stuff for Cois Fharraige specifically.
If you know the geographic region of your dialect, it's good to try and look for things labeled with the larger geographic region it's in and then narrow down, since often things aren't labelled specifically with "Cois Fharraige" (at least not in marketing) so you might have to look for "Connacht", then "Galway" then "Conamara" then "Cois Fharraige"*.
(e.g.) on teanglann.ie the pronunciation tab is just labeled "Connacht" but some of their speakers are from Cois Fharraige.
This is less necessary for Cois Fharraige specifically, but remember to be aware that geographically neighbouring dialects tend to be similar, so if you can't find a lot of resources about one dialect, a good starting point can be the closest one you can find. E.g. in Kerry, the Corca Dhuibhne dialect is a lot stronger than the UÃbh Ráthach dialect, and as such there's a lot more information about it, if you were looking to learn UÃbh Ráthach specifically, I would recommend starting with Corca Dhuibhne as a basis, and then shifting.
A Lot of Resources are in Irish
If you want information on specific dialects in Irish, often the information is only accessible in Irish. Books like An Teanga Bheo are in Irish, a lot of dialect studies like Gaeilge Chorca Dhuibhne are in Irish, so using whatever you can get your hands on to get started, and then transitioning/focusing once you're a bit more advanced is very reasonable.
Don't Shy away from Academic Sources
For specific dialect info, often the best info is in dialect studies, these tend to be called things like "The Irish of West Muskerry, The Irish of Iorras Aithneach, Gaeilge Chorca Dhuibhne".
Recommendations for Cois Fharraige specifically
The textbook Learning Irish by MÃcheál Ó Siadhail focuses on this dialect specifically so that's a really good place to start.
If you're looking for something more descriptive, An Teanga Bheo - Gaeilge Chonamara by Séamas Ó Murchú is quite good and mentions distinctions between subdialects in Conamara including Cois Fharraige*. But as mentioned it's in Irish. There is a translated version online here though.
If you want something really in depth, that's when you want to look for the dialect studies, Gaeilge Chois Fhairrge - An DeilbhÃocht by Tomás De Bhaldraithe is in Irish and gives a very in depth look at the dialect, and The Irish of Cois Fhairrge - A Phonetic Study also by De Bhaldraithe but in English talks about the pronunciation in the dialect. Note that Cois Fhairrge is spelt in a prereform way here, which also makes them harder to find!
Anyone feel free to add on if they know other resources for Cois Fharraige Irish.
*Cois Fharraige may or may not be a part of Conamara, depending on who you ask.