This awesome (free!) hat comes in sizes womens to mens medium. But my son has a big head. Making the smaller size (womens medium) with an 8ply/DK yarn (instead of 10ply/Aran) left my boy with a perfect fit!
It is written and charted, very simple to follow and repetitive, however, I still recommend paying attention. More often than I would have liked, I ended up going in the wrong direction with the triangles (rather than a 5, 4, 3, 2, 1 with the stitches, I would 5, 4, 3, 4, 5.. then have to drop the stitches down to fix them). But even with these silly mistakes on my part, I still got it done in a day.
My boy loves his hat and wears it to daycare everyday. I used this yarn from SkeiNZ - a natural silver Perendale yarn that I was lucky enough to receive in a goody bag at a local fibre retreat (Unwind) back in March. I used just shy of the hole 50gm/100m ball. (enough to add another 2 rows of ribbing at the start, but I didn't want to run short).
This hat is great and I plan on making one for myself with an Aran yarn, when I find the right one!