Ravelry is your best source for finding free patterns on the internet because it is a one stop shop. Any pattern available for free on the net is most likely listed in Ravelry. To search for only free patterns, select free->yes from the availability tab on the pattern search page. See below.
Note that you do need to register to get access to Ravelry. There is no charge, and they don't sell your e-mail anywhere. If you aren't already registered, do it. The only thing you will regret is the time you will loose to its fascinating pages.
The grandmother of online knitting magazines is Knitty. Free patterns, articles, reviews and more. What's not to love? All Knitty's patterns are listed in Ravelry, but you can also search Knitty.
Interweave Knits has a website called Knitting Daily, that offers free patterns, free e-books and patterns from back issues for sale.
For those looking for edgier designs, articles and more, get over to the AntiCraft. It's not just knitting...
Lots of yarn companies offer free patterns to go with the yarns that they sell. Here's some of them:
- Drops designs has oodles of wonderful patterns. Very stylish. Often updated.
- Lion Brand
Of course I haven't hit them all. These are just the ones that cross my path most often. Happy knitting and see you tomorrow night! (Maybe I'll have a vest with me....)