What a sweet little sweater! I say little, but the wonderful thing (there are actually quite a few wonderful things) about Tin Can Knits is that their patterns are written for SO MANY DIFFERENT SIZES! It is wonderful. This simple sweater is written from sizes 0-6 months to adult 4XL. It is a seamless, top down sweater that is part of their Simple Collection. This collection is a series of free patterns that walk you through all the basic skills you need to be a proficient knitter. While it is technically a "beginner" series, the patterns are really well written and great, quicker projects for more experienced knitters. With my little one on the way, I was looking for a nice project I could knit up between some of my other, more monstrous projects. I love that it is seamless; in my experience, babies do not like seams.
I have another of Tin Can Knits sweaters on needles and have my eyes on one of their new patterns. (A sweater that buttons in the back! How fun!) If you know how to do a basic knit and purl stitch, this pattern would teach you anything else you would need to complete this project. Like I said earlier, it is a really great beginner pattern, but it is such a great and well-written sweater that any knitter could enjoy knitting this.