Supplement your Duolingo Irish course
Alison.com hosts a course on Introduction to Irish. The course is free. https://alison.com/subjects/72/Irish-Language-Skills
It is structured by stating a sentence in Irish, and the english translation. It is useful to supplement Duolingo in that it has pronunciation, although the course is not as effective as Duolingo, it is a useful resource.
Alison is a company based in Galway, so I would expect the pronunciations to be in the Connacht dialect.
Just going through this, it looks like much more natural Irish, though it seems to have some weird translations (always using é/í as 'it' in copular sentences).
But otherwise, it uses much more natural Irish, such as sé instead of is é and t'iníon instead of d'iníon
I like that this course has dialect specific content, focuses on sentences you might actually say in conversation, and introduces the copula straight away. That said, listening to a text-only powerpoint presentation isn't my idea of an engaging language lesson. I second galaxyrocker's comment about the translations being weird (and in a few cases inaccurate). From my brief look, there doesn't seem to be much you couldn't get from Routledge's Colloquial Irish (the audio of which is free)
I agree with that, however it is another resource. Even allowing for the small errors.