I'll offer the perspective of a nursing working mother for those who have been told they cannot nurse after going back to work (you can!!!). I nursed my 3 children each for over a year. I had the standard 12 week maternity leave and then went back to work part time for a week and then my regular schedule after that. I even had a child with Milk/Soy Protein Intolerance and was able to continue nursing for 14 months.
First, relax and enjoy your baby. This is a special relationship you will have with baby that goes beyond mere nourishment. Only you can nurse your baby.
1. Get prepared: take classes (if offered), visit with a lactation consultant, read books, read online, talk with other nursing mothers. Ask what was the hardest part of starting to nurse a baby and what made it easier.
2. Utilize the resources of your hospital. Our hospital provided a lactation consultant to visit during our hospital stay as well as appointments (free of charge) after we were released. Lactation consultants are often nurses with special lactation training and can be of great assistance in making that nursing relationship work. I used them for each of my babies as each child was different. Don't be afraid to ask for help. While nursing is natural, there is a learning curve.
3. Make nursing about you and the baby. Find a comfortable place that works for you to focus, especially early on. I recommend a Boppy-type of pillow or other nursing pillow, soft chair with arm supports and a nearby table to place things like water, burp cloths, notebook and reading material.
4. Before you go back to work, buy the best breast pump you can afford (or borrow one) and try it out. Not only will you have a small extra supply of milk stored from these practice sessions, you will figure out how long it takes to pump the amount you need so you can visit with your boss about time and a good place to pump. There are now laws that require employers to provide the time and a private location to pump breastmilk. You cannot be discriminated against for pumping during work hours: reasonable accomodations must be provided.
5. Along that same line, introduce your baby to the alternate feeding method at least a few weeks prior to going back to work. If it is a bottle, know that baby will resist at first. Try and try again. Often dad or grandma or auntie has more success. Baby wants you but when hungry will eventually take nourishment from a secondary source. (Well, except for my 3rd child who would wait 5-6 hours for me and never really did take a bottle. I nursed her for 14 months and she never starved, LOL). Give yourself a few hours to leave the house and see if baby takes the bottle/cup/alternative method.
6. Find a child care provider that will support nursing. My daycare providers did and it worked great.They never questioned my desire to provide milk for my baby and had a safe place to store my pumped milk and a method to reheat it for baby safely. It helped that I worked a few blocks from the daycare so I could go and nurse during my noon hour, see my baby and drop off the afternoon bottle of milk that I had pumped that morning. Having that one extra time during the day to nurse (and not have to pump) was good for me and my babies.
7. Come home each day and love your baby and nurse him/her until you are both satisfied. It was the best way for me to reconnect with my baby after being apart. It's more than a hug and a cuddle, it was often 30 un-interrupted minutes that I spent looking into my baby's eyes and cooing and talking with just him or her...until interrupted by DH or older siblings, LOL. Life goes on!
Good luck for those out there wishing to begin nursing. It is work but the benefits are well worth it.