I have just recently bought the core game and began reading the book. I love both and would like to purchase some expansions. I don't really want to order them offline if there's stores near me that might carry them, but I'm not sure how to find that out. Are there any major retailers that carry AGoT? Or can anyone recomned a website that might be able to help?

You'll have to look for independent game shops in your area. You will not find these at Barnes & Noble or Target. We've got several local game stores that don't carry them regularly, but will order them if you ask. I just order them off Amazon. Amazon Prime pays for itself in shipping costs if you're into LCG's.