Mel:
As I recall from your earlier thread, you chose the biopsy under anesthesia...so you will have no pain during the procedure. Afterwards, a couple of tylenol should do the trick...but, as JT said, you could ask for a Vicodin prescription if you are concerned.
Depending on time of day for your biopsy, staying over the first night might be advisable. This is especially true if you plan to drive as you should not drive after the anesthesia. Staying a second night is overkill as you should be pretty much back to normal on the day following the biopsy. If you have concerns about your BPH, you should by all means discuss that with your physician...most of here are not doctors, we only play them on the internet!
Finally, as others have said, be prepared for some blood in your urine for a couple of days and some nasty looking ejaculate for a few weeks.
Most of all, good luck...I hope your test shows NOTHING and you can relax. In any case, please come back and let us know what happens...
Tudpock