Can anyone tell me more about a breast biopsy--what do they do, anesthesia, etc?

Core box w/local. The standard of care for most all breast biopsies are the diagnosis be made via a needle biopsy (core bx). This is usually done in the office under local anesthetic. The breast surgeon will generally use some means if image guidance - ultrasound or mmg/stereotactic - to ensure accurate targeting.
The biopsy. Can be done directed by ultrasound and/or needle localization. If the rsults are equivocal, it may be necessary to do an open biopy under general anesthesia.
Usually IV sedation. There are several ways of doing this procedure. It can either be a needle localizing biopsy or straight needle biopsy. Either involves the placement of a needle into the tissue that is to be examined, and a sample is sent off for a pathologist to analyze. The anesthesia for either of these procedures is usually IV sedation, with local anesthesia at the site of needle insertion.