I've ordered from KnitPicks, with wonderful results. KP has been highly recommended by others on this site, so I felt comfortable ordering from there. I'm glad you posted this because I've been wondering about other sites.
I found some Swedish yarns that I want but can't get at my LYS or from KP. I've found a few stores online that carry these yarns, but I don't know anything about these places, so I'm hesitant to place an order.
What do we need to look for to alleviate concerns for security when we do online shopping? One of my co-workers told me that what I need to worry about is what the company does with my credit card information after the purchase. Do they delete it, or do they store it somewhere? How can we find this out?