By now you should know about the June Baby Shower - a quickie campaign to collect wool hats and socks for babies in Kabul. Details are here on the A4A web page.
Socks should be of a size to fit newborns to age 1 year -- a minimum foot length of 2.5 (6.3 cm) inches and a maximum length of about 4 inches (10 cm). I have a list of patterns I am checking out, but I will not be recommending any until I have tested them myself. Here is the first on the list, and it is a good one:
This is Susan B. Anderson's Jelly Bean sock, a free pattern for worsted weight yarn, available here. (Scroll to the bottom of the blog entry to get the pdf.) The ribbing pulls it up nicely so that the leg fits snugly around my thumb, indicating that it will stay on a newborn, but it can stretch out to fit an older baby too. The cuff can be folded over when the baby is very young, or pulled up when he or she is older. I made this sock with Cascade 220 (I think), and I have shown it on a 1-inch grid so you can see the finished size. Make only the smallest size from this pattern; the others are too big. I am planning to knit the feet of all my socks to measure 3.5 to 4 inches from heel to toe so they will fit the baby for longer; these socks are going to some of Kabul's poorest families, and there won't be a drawer full of socks to draw from when the baby grows out of these.
As always, use a yarn that's at least 75% wool. Because babies this age don't walk in shoes, the socks can be made with a softer yarn than usually would be recommended for socks.
Making this sock was a lot of fun and took very little time (you cast on just 28 stitches). I will make the second one tonight and start stacking them up. I may never get to the smaller-gauge yarns -- these worsted weight socks go so quickly that I am going to be able to make a whole bunch for this campaign.