Born in Eretz-Israel to a distinguished family of Jews from Spain. Najara lived and worked in Damascus, Safed, and Gaza. He wrote in many fields, such as biblical commentary and sermons of Halacha. His main publicity came from his many songs, which he sang with his pleasant voice, often using melodies of foreign songs that were common among the Jewish and non-Jewish public of his time. He is considered to be one of the greatest Hebrew poets of the period after the expulsion from Spain.
Some of his works are still performed today, see in the JMRC concert Rabbi Yisrael Najara- the Original Versions.
Sources: Encyclopedia Judaica; Concise Encyclopedia of Jewish Music; Be'eri, Tova. Booklet of the concert- Rabbi Yisrael Najara- the Original Versions.
Further information about Najara can be found in "Song of the Month" of February 2010.
For full biography, see: Jewish Encyclopedia.
A more recent, though short, biography, can be found in Hava Tirosh-Samuelson's review of Mikve Israel.
Another more extensive biography can be found at Halakha of the Day.