Talmudic Books has published Soncino Babylonian Talmud Sanhedrin - the classic English edition of this important tractate.
My son Yitz reminded me that my father, Rabbi Dr. Zev Zahavy, who passed away on May 1, 2012, used to say that Sanhedrin was his favorite Talmud tractate.
Here is the book description, adapted from the Introduction:
The word Sanhedrin designates the higher courts of law which in the latter part of the period of the Second Temple administered justice in Israel according to the Mosaic law in the more serious criminal, and especially capital, cases. The main subject of this tractate is the composition, powers, and functions of these courts. Incidentally, as is only natural, it deals in some detail with the conduct of criminal cases; and in this way it forms, along with Makkoth, the chief repository of the criminal law of the Talmud.
When the Mishnah was compiled, towards the end of the second century CE, the Sanhedrin was already a thing of the more or less distant past. As an institution it does not seem to have survived the destruction of the Second Temple; it may even have been falling into decay for some time before that event. Consequently, the information about it given in the Talmud, in this and other tractates, has neither the fullness nor the precision that we could desire. Both Josephus and the New Testament contain references to what is called the "Synhedrion" of the Jewish people, which it is not easy to reconcile with what we are told about any of the Sanhedrin mentioned in the Talmud.
From this tractate itself we learn that there were two kinds of Sanhedrin — the Great Sanhedrin, with 71 members, and the Lesser, with 23. Both, according to tradition, were instituted by Moses, but the first date at which a Sanhedrin is mentioned as actually functioning is 57 B.C.E. In the Talmud the Sanhedrin is almost always spoken of as a purely judicial institution, and the name seems in fact to be interchangeable with Beth Din Haggadol…the great Court of Justice. The Great Sanhedrin met in the Lishkath Hagazith [Chamber of Hewn Stone] in the Temple at Jerusalem; the Lesser Sanhedrin [there seem to have been several of them] met both in Jerusalem and at other places. The Lesser Sanhedrin was also competent to try capital cases, but the Great Sanhedrin was the supreme Court of Appeal on all disputed points of law or religious practice.
According to the Talmud, the two most distinguished members of the Great Sanhedrin were known as Nasi [Prince] and Ab-beth-din [Father of the Beth din], while there was a third known as Mufla [distinguished]. The last named may have been a kind of expert adviser; the other two titles seem to have been purely honorary, and not to have denoted any official position. Certain it is that in Josephus and the New Testament it is the High Priest who is spoken of as the President of the Synhedrion, and this in itself seems inherently probable. Josephus and the New Testament also picture the Synhedrion as an institution of some political importance; whether this institution was identical with the Great Sanhedrin of the Talmud it is difficult to say.
In the eyes of Christian students, Sanhedrin has always occupied a favored place among the tractates of the Talmud on account of the light which it is capable of throwing on the trial of Jesus of Nazareth. It is not without significance that when Reuchlin, the Christian champion of Jewish learning, searched Europe to find a copy of the Talmud, the only Treatise he could find was Sanhedrin. For the Jewish student also, in spite of the fact that its main theme was already at the time of its compilation one of academic interest only, it possesses a peculiar fascination, partly on account of the fundamental importance of the legal principles with which it deals, partly on account of the wide range of its digressions and the exceptionally high quality of its aggadic material. In particular in view of their influence on the teaching of Maimonides, may be mentioned its famous statement on the limits of monarchic power, with the consequent disputation on the reasons for the Mosaic laws, and the celebrated eleventh chapter. which is the locus classicus for the problem of Dogma.