Nijay Gupta and Stephen Carlson have already posted their suggestions for presenting papers and handling comments at SBL. Although I have far less experience in this realm I thought I would recount some of my own experiences.
When it comes to responses to your paper Stephen Carlson is certainly correct when stating that “the questions reflect the interests of your questioners, not your own.” In addition to unusual questions your paper may provoke some completely irrelevant questions. During my first SBL I was seated next to a scholar who is known for his somewhat anti-social demeanor. The topic of the paper concerned some issue in Matthew. During the question period the scholar seated next to me bolted up from his chair and demanded the reader attend to him. Then said scholar asked the reader what she thought of the anti-semitic passages contained in Matthew and how she planned on removing them. This had absolutely nothing to do with her paper but she handled the matter quickly and gracefully. However, as she then turned to field the next question, said scholar shouted out to her exclaiming that she had not properly addressed his question. The reader again attended to the questioner with a bit more depth but explained to him that this was not her area of expertise. She handled the situation quite well, but I remember thinking that it was a rather difficult situation. I have not seen this occur very often at SBL but oddball questions can certainly occur. Try not to get too flustered if someone is out of line, the whole room will probably be rooting for you.
Something I do to prepare for a paper is to try to guess what questions a reader might have and prepare an answer ahead of time. For instance, I gave a paper in which I claimed that the Greek word ektroma was rather rare as a part of a larger argument. Since this was a foundational data point for my argument I concluded that someone might press me on the issue. Thus, I made a list of all of the appearances of the word in Greek literature and had them on hand. Sure enough this question was asked and I was able to provide the questioner with a complete list of the appearances of the word along with a summary of the literal and figurative uses of the word. While it may not always be possible to anticipate questions, it is worth the attempt.
Finally, I certainly agree with Nijay and Stephen who suggest fielding questions after the session. In the past, as a graduate student, I have been unwilling to ask questions during the session. However, after sessions I have always been eager to ask my questions (often more concerned with how the readers research affects my own research). Usually, there are already people surrounding the readers and I do not have the opportunity to ask any questions. However, there have been a number of times when I have caught readers as they were exiting the room in order to ask a few questions. Keep your head up and be ready for questions even when you think you are done.