I explain about the sweater, it is a very easy to crocheting them, in this pattern I use a double crochet and puff double crochet stitch, I explain about the puff stitch below the pattern row/special stitch. Some people use different ways to crochet puff stitch, it is very easy to understand. The band of the sweater, I made the front post and back post double crochet stitch.
To start this sweater first making the neck chain and follow the pattern. If you want to make a small size so you less them the increasing rounds and then continue work to the same. check the size to your babies.