This post was provoked by a student's request for some guidelines after some remarks I made in class about the danger of over-interpreting the Bible. I thought the comments might be more generally useful. If you follow this advice, you should save yourself from any major embarrassment in the pulpit.
First, use some common sense. If it sounds like it might be overly interpretive, it probably is, especially if you are a beginning student in the languages.
Second, make sure you know the grammar. By this, I don't mean that you've memorized Wallace's Greek Grammar Beyond the Basics or Waltke-O'Connor's Introduction to Biblical Hebrew Syntax. Instead, I mean that you have made use of the indices to look up the particular passage you're working on, or you've studied the particular construction you're interested in beyond what you might have picked up in your beginning language course. Grammar won't answer every question, or solve every dispute, but it will keep the beginner from making stupid mistakes out of ignorance.
Third, make sure you know the lexicography. If you're dealing with a particular word, or even a context, make sure you have consulted one of the major reference lexica. By this I don't mean Thayer's for Greek, or Gesenius for Hebrew. Unfortunately, I mean Bauer-Arndt-Gingrich-Danker for Greek, and the Hebrew and Aramaic Lexicon of the Old Testament for Hebrew. Yes, I realize the former is $120.00 in hard cover, and the latter is $216.00 from CBD. But these are resources that you will use for a long time. In addition, they may be available for your Bible software at a somewhat reduced price. Also, by "consulted," I don't mean that you looked up the word and scanned through the discussion for the meaning you want. What I mean is you read through the entry; you have considered the possible connotations of the word, and you have considered the limitations on those possibilities made by context. It is true that BAGD and HALOT are not inerrant, and academic specialists certainly have quibbles with particular entries, but again, they can keep beginners from stupid mistakes. All that being said, there is still a place for Thayer's and for the Brown-Driver-Briggs lexicon, especially as a place for beginners to start. The big reference lexica can be daunting for beginners who are overawed by the crowded page and the cryptic abbreviations that they present. In addition, with regard to BDB, the articles on the prepositions are mines of information in themselves. The beginner will learn a great deal about the functioning of the prepositions in Hebrew syntax from those essays.
Fourth, make sure you're familiar with the commentary literature. Again, I don't mean here that you have read all the commentaries on the passage, but rather that you have read a representative sample, enough to know the parameters on the meaning of the passage. Two caveats here. First, don't begin with the commentaries. Work through the passage yourself first, and be pretty comfortable with your understanding, then consult the commentaries. Second, most students read too many commentaries. My rule of thumb is 3-4, with maybe as many as 6 on a particularly difficult passage. Make sure that the commentaries you choose represent a variety of types. You should have at least one pre-critical commentary on your list. You should also have one that deals with technical matters of language and text. Then you should have one that is more sensitive to the theology of the text. Types two and three rarely co-exist within the same covers. Further, the pre-critical commentaries are generally much more aware of the theology and overall biblical context of the passage than are more recent ones.