I recently came across a post on The Jesus Blog which discussed a rule to balance new and old research taught by Dale Allison. In essence, he asks students to find a ratio for reading old to new works. Although Allison's particular ratio is not mentioned in the post, Anthony Le Donne suggests a new to old ratio of 3:1, that is, for every three new works read one "oldie but goodie." This is a great way to guide research in such a way that it remains balanced between new work and research that has had staying power over time. Take a good look at the comments where people weigh in on just which old texts are worthwhile to keep around.