Has anyone figured out a pattern for what sounds certain letters make? I have some of the basics down but maith is pronounced may and it just makes no sense
It definitely should not be pronounced as English "may"...
However, I suggest you look here for an idea about the orthography. You also have to realize that it's not English, and it doesn't use English's orthography (check out Manx for an interesting example of what happens when you put a Gaelic language with English spelling rules) or English phonetics (despite what this speaker my want you to believe). It really works a lot better if you don't try to come at it from an English writing view.
It looks pretty awful at first, but after a while you'll see most of the letter clusters get repeated over and over again.
My advice is to first thoroughly read the Wikipedia section concerning the orthography that galaxyrocker has linked, it's the best place to start; after that - start listening. Look up RnaG, and listen to their program.
I know that doesn't seem at all like something that could help you with reading, but just like there's only so many letter clusters, there's a limited number of sounds and their combinations. Once you get accustomed to it, you'll have an easier time figuring out how to read stuff because you will automatically know what fits with "the sound of the language" (I guess this is the auditory equivalent of "eyeballing it"; never 100% accurate, but usually close enough).