http://crochetcollection.blogspot.com/2008/02/free-crochet-snowflakes.html This might be a new one given the 2008 date but the sites it references are for the most part ones I used, I think.
Two books I would not want to be without are 99 Snowflakes (Leisure Arts #3013) and
Crochet 101 Snowflakes (American School of Needlework No. 1217) by Delsie Rhoades and Kathy Wesley (1995)
Along the way, I learned I liked the flake patterns that were mostly chains for working but more solid looking for aesthetics. Good old white school glue, waxed paper, foam core board and rust proof pins are essential for stiffening the flakes, if you like them like that. More glue than water is essential to keeping mostly chained flakes looking their best (too much water in the mix and the droop sadly before the Christmas season is over). There are groups for people who do nothing but crochet snowflakes. Snowflakes can be joined together to form lacy place mats and tablecloths. Smaller flakes make nice adornments for coats and fabric purses or headbands for girls.
Enjoy the links. There are plenty out there. There are even a few beading sites that have beaded snowflakes that are pretty neat. Done in tiny size 10 or 11 seed beads in either white or silver or clear (or combination of those) they make nice earrings or a pendant for a chain. You can also add beads to your flakes. Pre-string or grab as you go and put them in where ever you think is a good spot. I did a couple in baby blue beads and red beads. After all these years, I still don't know if I like them.
Lastly, throw in a few icicles to keep things interesting. There are a few patterns for them as well. Enjoy!