For an excellent summary of Judaism in Jesus’ time—one which makes judicious use of rabbinic evidence—see E.P. Sanders, Judaism: Practice and Belief 63 B.C.E.–66 C.E. (London: SCM Press, 1992). For more on the use of rabbinic sources, see Sanders’s Paul and Palestinian Judaism: A Comparison of Patterns of Religion (Minneapolis: Fortress Press, 1977), esp. pp. 59–84.