In addition to the excellent sale Webs is having that someone mentioned,
Personal Threads is having a sale 20% off everything in stock.
Also Ram Wools will be having a sale 30% off everything in stock starting, I think, Jan. 3rd. I don't think I'll be able to resist this one.
Also Yarn4Socks is having a sale of 20% off everything in stock, too.
Red Bird Knits is also having a sale 30% off yarn and needles, 40% off books. This is a great one, too.
Everybody is having a sale these days, trying to make me broke. check each site for when their sales end.