The blogs Just Hungry and Just Bento have some great Japanese (and other) recipes. Some of the ingredients are pretty specialized, and she often suggests substitutions. I really recommend at least trying to get hold of some miso paste (the main flavoring in miso soup) as well as soy or fish sauce if you're trying to get salt into your diet. It's delicious, it can be added to so many things, and it goes a long long way.