The sockie I have on the needles atm is aimed to fit a ~2-3 month-old with long feet. I said 'daringly' because I usually hate #2s for socks (I think the fabric they make is too loose and rough, but it seems to be not so rough in the Lorna's, and in a baby that's not even crawling yet, the soles aren't going to see much wear)but I wanted a looser fabric for these than I get on #1s. For your (Peggy's) little guy, I would say, do the standard sock-fitting measurements and go from there. I don't know how much is left on your ball(s), but I would guess you can get socks for him. After all, your feet are almost certainly smaller than mine. ^^;
Two books I found invaluable for learning to make socks: The Twisted Sisters Sock Workbook and Nancy Bush's Folk Socks. Twisted Sisters I only look at occasionally anymore, I've absorbed all the sock wisdom out of it I need at present, but Folk Socks sits easy to hand at all times, and I still refer to it frequently, for both technique and patterns, and this is 4+ years into my sock-making obsession. Nancy Bush's other socks books are, of course, also great, and I want to own those I don't already, but I think Folk Socks is best for sheer basic technique.