I should like to introduce "The Easter Rising in Song & Ballad" edited by C.Desmond Greaves. The first edition was published for the Workers' Music Association by Kahn & Averill, London in 1980.
This book contains more than 30 songs with notation concerning the 1916 rebellion including "A Rebel Song (James Connolly)", "The Soldiers of Cumann Na mBan (Brian O';Higgins)", "James Connolly", etc. You can learn not only the songs but the Irish history. I am not quite sure if this book is still available.