Camden Town is the perfect place to go if you want to get a bunch of souvenirs. You can get the England zip-up track jackets that everyone has or wants. Don't be alarmed by prices; you can usually talk someone down in price.
Don't bother to buy shoes. Most of the stores lack good customer service and will not help you if don't look like you are going to buy something. Plus, they are overpriced for the quality, and you can't really barter with them.
Try to find the old horse stable. If you are into antiques, you can find old dishes and silverware and books. The vendors here are very friendly. One man struck up a conversation with me because he thought I was from California (I was wearing a University of Southern California sweatshirt). There are lots of food vendors, and getting a quick, cheap lunch is not difficult.
There is a Doc Marten store if you walk to the left of the tube station as you come out. This would be the best time to get them! While the exchange rate may make it more expensive, they can custom-fit them, and sometimes, just sometimes, the shoes are cheaper there than here in the States.
Take the Northern Line to Camden Town tube station.
Camden Market is also a great place to find a cheap lunch and you can find anything from fast food to Indian to Moraccan to Crepes to African...Everything. My friends were wild about the Chinese food they found there it was only TWO POUNDS!