Although you asked for responses from dual career households, I thought that my experiences as a single Mom might be helpful to you.
As you can imagine, being single, I didn't have the option of not going back to work. I chose to take my FMLA leave intermittently, rather than all at once. I took a week in December off and all of January off. In February, I returned to work 2 days a week. Next week, I begin working 3 days a week, which I'll do until May, when I'll go back 4 days a week. In June, I expect to be back to full-time.
Regarding daycare -- in my area, infant daycare is
very hard to come by. I put my name on a waiting list for one of the best daycare centers in my area the day I signed with my adoption agency! This particular daycare does not have a lot of turnover and getting a spot can take months or even years. We lucked out and got a part-time spot that began in November. Of course, we weren't completely lucky as my son wasn't home when the spot opened up, but I paid for it nonetheless to save it. Luckily, the part-time spot became full-time this month. I won't be putting him in full-time daycare until June, but at least I know that we have the spot, which, of course, I have to pay for even though we're not using it.
I strongly recommend that you start researching daycare now. You can start by finding out which agency in your State gives daycare referrals. In my State, the State Department of Health and Human Services delegates this responsibility to Easter Seals. Every State is different, I believe. In any event, you can contact the referral agency and tell that agency what you're looking for (e.g., infant daycare in either daycare centers of family daycare situations in a certain geographical area), and the agency will send you a list of entities that meet your requirements. Then you can start calling and visiting.
If you're going the daycare center route, you might want to focus on centers that are accredited by the National Association for the Education of Young Children (NAEYC). The accreditation process through that NAEYC is rigorous and centers that NAEYC accredits tend to have lower staff-child ratios, etc.
Good luck to you!!