As you know, I have just translated this commentary into English, and you can get a copy either by e-mailing me, or from Amazon, or from the publisher - www.torahlab.org (If you order it from me I'll even sign it for you if you want).
Also from torahlab you can see a couple of pages from the book as a sample. This is Rabbeinu Yonah's commentary on one Mishna
Here is a biography of Rabbienu Yonah written by Rabbi Yaacov Haber, taken from the book.
Rabbi Yaacov Haber
“There were many great Torah authors and many styles of mussar. Not every author can speak to every soul; there are after all so many different types of souls. The exception to this is Rabbeinu Yonah Girondi (and specifically his book on teshuvah). His writings are appropriate to every Jew in every time. (Rabbi Chaim of Velozhin as quoted by the Chofetz Chaim)
Rabbeinu Yonah came from Girona, in Catalonia. He was a grandson and student of the Ramban (Nachmanides), and the teacher of the Rashba. He was also considered the most prominent pupil of Rabbi Shlomoh Min HaHor who was the leader of the opponents of Rambams' philosophical works. As such, he was one of the signers of the infamous ban proclaimed against the Moreh Nevuchim and the Sefer HaMadda in 1233. According to his pupil, Hillel of Verona, Rabbeinu Yonah felt that these editions were philosophically dangerous to the masses and was the instigator of the public burning of Maimonides' writings by the church in 1233.
Nine years later, in 1242, twenty-four wagon-loads of the Talmud were burned by the church at the very same place where the philosophical writings of Rambam had been destroyed. Rabbeinu Yonah, realized that he made a mistake and publicly admitted in the synagogue of Montpellier that he had been wrong in all his acts against the works and fame of Maimonides.
In his repentance he vowed to travel to Eretz Yisroel and prostrate himself on the grave of the Rambam and implore his pardon in the presence of ten men for seven consecutive days. He left France with that intention, but was detained, first in Barcelona and later in Toledo. He remained in Toledo, and became one of the great Talmudical teachers of his time.
In all his lectures and in his writings he made a point of quoting from Rambam; always mentioning his name with great reverence. Rabbeinu Yonah’s sudden death from a rare disease was considered by many as a consequence of failure to fulfil his vow to journey to the grave of Rambam. He died in Toledo, Spain in November of 1263.
It is surmised that Rabbeinu Yonah wrote a number of works to atone for his earlier attacks on Rambam and to emphasize his repentance. His Iggeres HaTeshuvah, Shaare Teshuvah, and Sefer HaYirah are among the most popular ethical treatises in the Judaic library. The Shaare Teshuvah first appeared in Fano (1505) with the Sefer HaYirah, while the Iggeres HaTeshuvah was first published in Cracow (1586). All have been reprinted many times, separately and together, as well as numerous extracts from them. Rabbeinu Yonah actually wrote many more treatises which were compiled together and published as Shaarei Tzedek; unfortunately most of these writings have been lost.
The great Gaon Rebbe Akiva Eiger commented that he enjoyed studying the mussar works of Rabbeinu Yonah because aside from being a great ethicist, Rabbeinu Yonah was one of the greatest Talmudic scholars of all time as well as a authority on Jewish law. He is mentioned several times in the commentary of the Tosafos on the Talmud, referred to there as Rabbi Yonah.
 ethical reproof and guidance.
 repentance; ref. to Shaarei Teshuva
 Rabbi Yisroel Meir Kagan of Radin,( Poland, 1838-1933)
 Rabbi Moshe ben Nachman, also known as Nachmanides ( Spain, 1194-1270)
 Rabbi Shlomo ben Aderet, (Spain,1235-1310)
 Rabbi Shlomo of Montpellier in Provence (12th century)
 Rabbi Moshe ben Maimon, also known as Maimonides (Egypt, 1135-1204)
 Hillel ben Solomon of Verona (Italy, 1220-1295)
 Pope Gregory IX believed the problem of heresy needed serious attention and was not content with leaving it to the bishops, who might have been negligent, but extended Papal control in this fundamental area as well. In 1231, he established the Papal Inquisition to deal with it. As part of their response, they instigated the burning of controversial works, often after public debate, including the writings of Rambam, the Talmud and the commentaries of the Tosafos.
 Posen (1761-1837)
 Thirteenth century commentators on the Talmud the leaders of whom were the grandchildren of Rashi
May His Soul Be Bound in the Bonds of Eternal Life