Understanding the history of the Irish language may help you teach it more effectively to students. The earliest recorded evidences of the Irish language date back to the 4th century. It was widely spoken throughout Ireland until the 19th century when the British government enforced a strict "English-only" rule in all national schools. As you teach the language, interweave grammar with history showing how its waxing and waning correspond to sociopolitical events in Ireland.
The BBC's Gaeilge website provides excellent resources for teaching the fundamentals of the Irish language along with its three main dialects: Munster, Connacht and Ulster. Refresh your own or your students' understanding of Irish dialects at Irish Language and listen to differences between the three online.
Teach your students common phrases in the three dialects of the Irish language. Resources are available online from Irish Sayings that provide more than 400 common phrases written and spoken in the three dialects of the Irish language. Work through the phrases together in class. Work through numbers together as well. Use an online dictionary such as Irishionary, which not only provides translations from English to Irish but is use based and interactive, providing a forum for you to connect with other educators and learners of the Irish language.
Irish-language grammar and vocabulary resources can be found online from organizations like Daltai, which is committed to teaching and celebrating the Irish language. Samples of verbs in present, future, past, conditional and other tenses are given along with common phrases and proverbs. Games and classes provide engaging instruction in the teaching of the Irish language.