I would like to write a post full of helpful advice for working moms...but I am not the guru of the topic, and in fact struggle quite often, so I will rather write a post with what I found that works for me. Pick and choose what might seem helpful.
I went to work when Emma was 5 months old. I work in the afternoons only, from 1 pm to about 4:30 pm. Sometimes I run late and stay until 5 pm, and sometimes I get called out during the night, but that is no more than once every 1-2 weeks, for a few hours at a time.
The best thing that I did was to get Emma on a schedule. We had no schedule before, we would sleep in late, stay up late, and nap together whenever the urge struck us. Having a regular sleep-wake-nap schedule is extremely important, as it is the backbone of any activity done with a baby. Everything we do has to fit in between 10:30-1 pm or between 4-6 pm, her awake times. Evenings are off limits, as she is very cranky and needs to have me give her attention non stop, preferably at home.
The second thing that we needed was to have her take a bottle regularly. She does take the bottle and the breast with equal ease. At work she has one full bottle, and some baby mum-mum crackers. I breastfeed at 11 and then at 5 pm, with a six hour break, and this hasn't affected my production at all. Probably because she feeds every 2-3 hours all night long at the breast, so I only get one long break from breastfeeding in the span of 24 hours.
The third thing was to decide what to do about diapering. We use cloth diapers at home, but to carry the cloth diapers to work is sometimes difficult. So far, we had a couple of the hybrid G diapers inserts, which are disposable biodegradable flushable inserts that go in the G pants (the G pants are basically a cover and a waterproof layer, forming the outside shell of the diaper. The inserts go inside, and for G diapers the inserts can be cloth, which is what we have used so far, or this biodegradable flushable gel-filled inserts). I don't know if I should continue with that, or try to convince the nanny that carrying stinky poo-stained cloth diapers in the diaper bag is chic after all.
The fourth thing: get the baby used to the nanny. I was lucky to have my mom help so far, as Emma loves my mom. In fact, there are many days when I doubt she is clear on the fact that I am her mother, not her. Luckily, I have the boobs, so I still present some interest to the little lady, otherwise she would ditch me for my mother :) In two weeks, however, my mom has to go home and I need to introduce Emma to the new nanny. She cried the first time she saw her, and could only be in her arms for a second. I have a lot of work to do I'm afraid.
Fifth (in no particular order): decide on about four dishes that are easy to cook and keep in the fridge for up to four days (if they don't then get another fridge, most food should keep that long in a well functioning fridge). For us, they are: moroccan chickpeas (with coconut milk, yum!), salmon (steamed, a portion every day), beans with vegetables, and lamb or bison curry. I rotate through these every few days, having two at a time in the fridge, and eating one every second day (like this: cook chickpeas on Sunday, eat them, cook fish on Monday, eat it, cook fish again on Tuesday, as I like the fish fairly fresh, eat it, eat chickpeas again on Wednesday, then cook beans on Thursday but eat any leftovers from either fish or chickpeas, and eat the beans on Friday, cook the lamb on Saturday and eat it, beans on Sunday, lamb on Monday, cook something else on Tuesday but eat leftovers.
I guess what I am trying to say about the food is: eat leftovers. You can make a quick salad to go with it. Even if you cook a dish one night, cook it after your child is in bed and eat it tomorrow. Do not expect to come home from work and cook dinner and then eat it. It is too much for the child. He or she wants you to give him/her attention after you come home, not to cook dinner. That is just my experience. Do the cooking while child is in bed for the night, i.e. after 8 pm. My leftovers are just as good or better the next day. The only exception is the fish, which I just plonk in the steamer and eat freshly cooked, as I am not a big fan of leftover steamed salmon. The second exception is the weekend, when I have time to cook during the day and we can eat right away.
Other miscellaneous advice involves: get someone to help clean the house. This is precious time you have to spend with your child, and it is worth paying for. I am going to add to my usual 3 hours of housekeeping a week a further 1-2 hours on the weekend. I used to think it is an indulgence, but I think it is worth the sacrifice. I just don't have time to clean, my life is really regimented and Emma hates it if I do anything that doesn't involve her. I barely have time to water the plants and change the pets' water. With all this housekeeping, you'd think you could eat off my floors, but actually there is still cat hair on the couch, dust on the carpets, and crumbles on the linoleum on a regular basis. (Part of the problem is that my housekeeper is old and really slow, hopefully she never reads this blog...).
Also on the miscellaneous list: get some kitchen gadget like the Thermomix that cooks for you so you don't have to sit there and stir the food. I just throw all the ingredients in and set the timer, after which it is all done. A crock pot might do the trick, I just don't use it so I can't give advice as to what to do with it.
I hope I haven't left out anything important, but if I did I am sure somebody can point it out in the comments section :)