Abair! faclair by R. W. Renton & J. A. MacDonald. Gairm Publications, reprinted by
Clò Raghnaill. ISBN: 0-9551362-0-2 or 978-0-9551342-0-7. You can get it at
Comhairle nan Leabhraichean. An excellent little beginner's dictionary, because it's both Gaelic-English and English-Gaelic, and also lists irregular forms, and the nouns in their different forms with the article. It doesn't include the pronunciation though.