knitting a baby hat

[OHmama]

http://www.bevscountrycottage.com/abctree.html#KNITHAT Is the knitted cap on that page your pattern?

That one calls for LB Pound of Love, Knit: 19 stitches x 24 rows = 4" (10 cm) on size 8 (5mm) needles. The yarn you linked to says, Knit Gauge: 16 stitches x 24 rows = 4".

You might consider running to Walmart or some place similar and picking up some LB Pound of Love or at least look at it and feel it to get an idea of how the two compare. I'm knitting with LBPoL to make a sweater. It's so soft, I love it.

If you want to look at other patterns, here's a search result on ravelry for Easy Newborn Beanies. http://www.ravelry.com/pattern