
There are many free pattern sites on line.
Join Ravelry - they have lots of patterns that are free. And it's a great place to find people with interests similar to yours, who happen to knit or crochet. It also has great tips for things - like how to remove smells from old yarn..
http://www.ravelry.com/
Other great free pattern sites:
http://www.knittingpatterncentral.com/directory.php
http://www.crochetpatterncentral.com/directory.php - this site has a great collection of crochet patterns. Under their “flower” section, they have many flower patterns which are easy to make and look wonderful on hats. You can also embellish hats with buttons or beads.
(http://www.crochetme.com) on line crochet magazine - good patterns
http://www.chemocaps.com/ has lots of KNIT patterns, but not a lot of photos.
http://www.bevscountrycottage.com/cancercaps.html knit and crochet – cute bear cap for kids…
http://patbythehook.blogdrive.com/ lots of hats – all crochet
http://www.stitchdiva.com/ProductInfo.aspx?productid=SDS-019
All knitting – good links http://mathomhouse.typepad.com/photos/chemo_caps/pink_ribbon_bbcdotcodotuk.html