Yossi ben Yochanan
Rabbi Yossi Ben Yochanan studied under Antigonus Ish Socho and later served as the vice president of the Sanhedrin under Yossi ben Yoezer, together forming the first set of Zugot. During their leadership the first Halachic disagreement in Judaism took place. They led the Jewish nation in the era proceeding the Macabeen revolt, a time when the country was greatly influenced by Hellenization. Yossi Ben Yochanan's students were Yehoshua ben Prachya and Neti Harbeli.
Av Bais Din
Yossi ben Yochanan originated from Yerushalaim and was a disciple of Antigonus Ish Socho, in his youth studying under Shimon HaTzadik. After the passing of Antigonus, the leadership was split in two and Yose ben Yochanan served as Vice President of the Sanhedrin while Yossi ben Yoezer served as president and Nasi. Their leadership was the first from five sets of Zugot.
It was at that time that the first Machlokes arose in Yisroel regrading doing Smicha on Yom Tov. Until Yossi ben Yochanan all the leaders would teach the Torah exactly as it had been transmitted from Moshe Rabbanue, from then on the Torah was no longer transmitted in its perfect form, since the Machlokes of the Smicha had risen.
After Yose ben Yochanan passed away it was said the 'grape clusters' had ended. Grape clusters in Hebrew are Eshkolot, which can be read as Ish Kol - a man containing everything, referring to Yossi ben Yochanan who contained full knowledge of the Torah and completely perfected character traits.
Yosi ben Yochanan is known for his three teachings in the first chapter of Masechet Avos. He said "Your home should be opened widely, paupers should be members of your household and do not talk more then necessary with a woman".
Your house should always be open to guests in a very welcoming way, similar to Avraham who had four entrances to his home in all directions, showing all visitors they were welcome.
Hospitality to Poor
Be extra careful to treat poor guests with respect as they are extra sensitive.
Talking to Women
Yossi ben Yochanan taught this statement regarding a person's own wife and it certainly applies to other woman. A person should be careful of how he talks to his wife while she is a Nida, so it does not lead him to sin. Additionally if a person tells his wife how he was insulted by others, she will push him avenge his honor and enter a feud. If a person tells his wife how he was belittled, she will lose respect for him as well. Over speaking with a a wife also leads to very mundane conversations which distract a person from Torah and Avodas Hashem. In general talking to women can lead to lust and then sin.
Kever Yose ben Yochanan
Yossi ben Yochanan is buried in the area above Wadi Amud in the outskirts of Tzfat. According to Rabbi Chaim Vital he is buried in a cave along with Yossi ben Yoezer and Yossi ben Meshulam. In his description it states that it is on the way down to the wadi from the Kever of Brey Drav Safra. This cave has its entrance in the roof and contains three crevices in its western end, each containing the burial place of one Tzadik. Currently the exact whereabouts of the cave are unknown.