Duo-Lingo: Fun and Free, step-by-step course available online or App: www.duolingo.com
Learn Irish with Liam O Maonlai: Free Irish Course from the Irish Independent Newspaper. Just download and listen!
http://www.independent.ie/life/family/learning/learn-irish-with-liam-o-maonlai-26460087.html
Easy Irish : More free audio files. From 'Greetings' it gradually builds understanding through a series of 28 short lessons (Northern dialect)
http://www.easyirish.com/category/easy-irish-podcasts/
Des Bishop - In the Name of the Fada : TV series following stand-up comedian Des Bishop's efforts to learn Irish fluently within one year. Funny and inspirational - "Níl sé deacair"
https://www.youtube.com/watch?v=uPqoKpyhzP8
One of the best online Irish-English dictionaries can be accessed at: http://www.teanglann.ie/en/
Check out TG4 (Ireland's Gaelic TV Station) for lots of great documentaries and tv shows aired through Irish that are usually subtitled in English.
http://www.tg4.ie/en/player/home/
BBC: Giota Beag ('a wee bit') is a free audio course for Irish language beginners.
http://www.bbc.co.uk/northernireland/irish/blas/learners/beag1/lesson1.shtml
Then try Beag Eile - 'another wee bit'.
http://www.bbc.co.uk/northernireland/irish/blas/learners/beag2/lesson1.shtml
And, just for fun:
8 delightful Irish words and phrases that English could never match
http://www.dailyedge.ie/the-irish-word-for-2496455-Jan2016/
How to curse in Irish: https://www.youtube.com/watch?v=jyfx0gUALxk
(list Courtesy of Tir na Saor)