Once a month cooking
For years I did the 'once a week' cooking, which has the advantage of not requiring much freezer space (which I didn't have, with my under-counter apartment fridge).  Part of the trick was cooking something that could be used multiple ways with minimal effort -- a blend of ground beef, onions and peppers could be turned into a pasta sauce, mexican food, etc.

These days, I still don't go quite to the extreme you're talking about, but I will do things like make way more than I know I'm going to use right away, and freeze the rest -- chili, black bean soup, stock, lasagna, etc.  When chicken's on sale, I'll poach a large batch, shred it, then freeze it in zip top freezer bags.  I can turn it into chicken tacos in a few minutes -- thaw with some water in a pan, add spices, and cook 'til the water's mostly boiled off.

Now, as in the past few months I've made a lot of meals for my brother's family while his wife was pregnant with twins, some considerations:


containers : you're going to need a lot for a month, especially if you're preparing sides and such.  As I had a membership to Restaurant Depot, I was able to get 2 1/4 lb rectangular aluminum containers normally used for carryout packaging.  Of course, I had to get a case of 400 ... if you know a restaurant that uses 'em, you might ask if they'll sell you a few dozen.  You want something that seals tightly, and you'll want to fill them so there's not much air space left in them.
labeling : all containers should be marked with what's in them (if you have to open to look, it's not going to last very long), the date it was made, and possibly reheating instructions and/or ingredient lists (see below).  My mom would use masking tape to label things, I just got the lids that had paper on one side, aluminum on the other.
variety : my sister-in-law started getting heartburn from some ingredients (tomatoes, onions), which meant that the items I had made didn't work out so well.  (She was fine after the pregnancy, though, and made use of the dinners then).


One thing I've heard about, but never done myself, is people who have a dinner exchange -- sort of like a cookie exchange for the holidays -- everyone makes up a number of casseroles, or whatever, and then people meet up, and everyone takes one of everyone else's items home.  So, if you're thinking about doing this, and know of other people who might want to, also, you might be able to get some extra variety.  (of course, if you don't like their cooking, it might not work out so well).

... and one last thought -- it won't help on the baby preparation front, but if I were going to do this as a regular thing, I'd consider making one or two recipes, with batches for 4-5 dinners each ... so I was staggering things, and not having to spend a whole day (or weekend) trying to make enough different things to have variety for a whole month.