I used Sirdar Baby Bamboo yarn and made the 12-18 month size. I used 4 balls, plus just enough of a 5th one to finish the last 2 rows of the edging, and I used 3.5mm needles. I actually did a tension swatch, which I admit that I never used to do, but it was worth it for this sweater. Baby Bamboo is a lovely yarn to knit with, but it is quite heavy, and you need more than you'd expect.
There are errors in the published pattern, but you can find the corrections on Ravelry or elsewhere. I would normally write them here, but an enthusiastic toddler got to my pattern with a pencil and it seems my hand-written corrections have been scribbled over!
I seem to have a tendency to flit between projects, between knitting and sewing, so I need to force myself to finish things! I made a 'to-do' list of my sewing and knitting projects, and the length of each list is slightly daunting, but definitely helps me focus on getting projects finished, if only so I can check things off the list!
Now off to finish the next knitting project!