Breast surgery is a biggie. Removing as much of the unknown goes a long way in reducing anxiety: 

Step 1:  Talk to your breast surgeon about what your options are.  Single mastectomy, bilateral mastectomy, delayed reconstruction, immediate reconstruction or breast conserving surgery.  What kind of reconstruction?  With reconstruction, you will need a plastic surgeon as well as a breast surgeon.  Once you know your options, do your research and find out what is best for you.  Consider your lifestyle, personal beliefs, personal feelings about your body and your breasts, insurance/financial issues and how long you will need to be off and be on lifting restrictions. 

Step 2:  Once you know what surgery/reconstruction is right for you, get it scheduled.  Once scheduled, you will need to pre-admit with your hospital.  This is a process (usually) where they collect and enter all of your demographic information, medical history and information and carry any preop orders such as lab work, chest x-ray and EKG.  This process can take around 2-4 hours depending on how busy the hospital is. 

Step 3:  Prepare your self and your loved ones for surgery.  Make child care arrangements as you could be in the hospital for 1 - 3 days.  Get your groceries stocked up as you won't be able to life anything heavy.  Get help arranged to make sure laundry and housekeeping can be done.  With mastectomy, you should not lift, push, pull, or carry anything heavier than a gallon of milk.  (ladies with large purses beware! you may need to temporarily downsize).  Make sure you report all of your medications including over the counter medications.  This is very important. 

Step 4: Prepare for the hospital:  Front closing, loose fitting, easy to wear clothing is important for days immediately following surgery.  Also, be sure to take your slippers to walk in.  If you have access to a mastectomy supply store or a nurse navigator who can get it for you, get a post mastectomy camisole (I use the Amoena Camisole).  These are designed with pockets to help manage your JP drains post operatively.  Stabilizing the drain tube at the insertion site decreases ALOT of irritation.  You can also get a soft leisure bra from the Reach to Recovery program of the American Cancer Society.  Again, check with your navigator as many hospitals and clinics do this on site.  If you have alot of friends and family who will be visiting, get yourself a "guest book" of some kind.  Then you can place that at the door for people to sign when you are resting and should not be disturbed.   You may have a catheter to drain your bladder immediately post op but when that comes out, you will be able to wear your underwear again. 

Step 5:  Generally, you can have nothing to eat or drink after midnight the night before surgery.  If you are diabetic or are on heart medications, make sure and clarify with your surgeon if you are to take those medications the morning of surgery or not.  Also, clarify when you should stop and when you should restart and medications that "thin" your blood such as Plavix, Coumadin and Asapirin.