I have been exclusive pumping for almost 5 months now and its going great. It takes a very supportive person with you to get everything accomplished sometimes but it is totally worth it. I wish you the best of luck!
first and most important, get a good pump. I have been using the Pump In Style. It works great at home and if I pack it up and take it places. All of the extras you can get with it are awesome. We also use the bottles that come with it for feeding and the storage, pumping, feeding is as simple as can be. Medela has a great program.
As a warning, you will go up and down with thoughts and feelings and want to give up but I have found that searching online for support is helpful. In the beginning pump as much as you can. You need to be pumping at least every time the baby eats (every 2-3 hours) plus one. This is what I did to help with my production. I also keep a daily log of every pump so i can see how much I am getting each session. I can then look back and see what I did that may have had an effect on my amount. (for instance when I took sudafed it decreased about about 2 ounces a day) As my little one got older and was taking out feedings l played with the times that I pump and now I have a schedule that is working great. I would highly suggest making a schedule and sticking to it but understand that things may change. Always make sure you plan that extra 20-30 minutes before walking out the door to make sure that you are comfortable out and about. Once I returned to work it was difficult to find times that were convienent and I continued a 2 am pump even though the baby was sleeping through the night. At 3.5 months I finally gave in and decided that I need to sleep through the night too and after a short decrease in production I was able to work it back up with extra times during the day. I do supplement with one feeding of formula a day but that is for my sanity. I was always concerned that I wouldn't have enough and wanted to get a frozen stash started so at 3 months we started one feeding of formula a day. I now have 8 days in the freezer!
I wish you the best of luck with your pumping and little one. it is the best you can give them!!!!! Stay positive and don't forget time for yourself, take a bath, a walk, or even run to the grocery by yourself if you have too. You have to take time to heal.