C.,
You should check out the book, Good Night Sleep Tight, by Kim West, "the sleeplady". I hired her as a consultant a couple of years ago to help me ween my daughter and help me to train her to go to sleep in her crib and stay asleep. I could not do the "cry it out" method, and Kim's approach is much more gentle.
I'll give you a summary of the steps, but first a few thoughts if you decide to keep nursing a while longer. I nursed my daughter for 18 months and my son for 15 months. I pumped at work for the first 9 months or so, but then I weened them from nursing during the day (so I could quit pumping) and just nursed them first thing in the morning and at night. If you did this, you could go back to work, and still enjoy the close bond of nursing your daughter at night and in the morning. Your body adjusts pretty quickly to the new nursing schedule.
When you decide to ween her completely, first, get her used to taking a bottle during the day and just nurse at night. Then time your night nursings. If you are nursing her for 20 minutes before bed, decrease it by 2 minutes every night. In addition, separate the nursing from falling asleep. I would nurse Kate with the lights on, sitting in a rocking chair, then, when she is sleepy, but not asleep, put her in her crib. Kate was sleeping in our bed, so I was also training her to sleep in her crib during this time. The Sleep Lady "shuffle" is outlined in her book if you are doing this, too. Basically, you stay right by the crib the first 3 nights and sooth her until she goes to sleep, then you move your chair 1-2 feet away and sooth her with your voice until she goes to sleep for 3 more nights, then you move closer to the door...for 3 more nights, then outside the door for 3 nights, then for the next 3 nights, you put her down and slowly leave the room and go away for 5 minutes at a time. This process worked great with both of my kids and surprisingly, there was only minimal crying.
Also -- once the kids were weened, I'd keep a bottle of water in their cribs so they could get a drink if they needed one. Water is much better for their teeth.
Anyway, hope this helps!
L.