HI, I too am knitting hats to donate and here is a quick favorite. It is free on Ravelry:
Worsted weight yarn )Aran)and size 7US needle, circ or dpn's
cast on the following: Men 88st, women 80st, child 72, toddler 64 (up or down by mulitple of 8 to adjust size)
Work in K2,P2 ribbing for 2" (all hat sizes) THEN
Switch to K6,P2 around all rows for
mens 6 1/2", Womens 6", childs 5", toddlers 4 1/2"
Decrease (all sizes)
R1: K6, K2tog around the row,
R2 (and ALL even numbered rows) Knit entire row
R3: K5, K2tog
R5: K4, K2tog
R7: K3, K2 tog
R9: K2, K2tog
R11: K1, K2tog
R12: K2tog all row
Cut yarn and pull tight
Pom pom optional.
Good luck, these are fun and quick.