Barbara Fisher of Tigers & Strawberries put together a really useful post for people who like to cook Chinese food at home, Staple Ingredients of the Chinese Pantry, in which she discusses her favorite brands, what qualities to look for when buying a particular item and how they're generally used in cooking.
What I liked most about her list is that she gives you a short but concise summary of why each item should be a regular fixture in your kitchen. For example, we all know about soy sauce, sesame oil and dried noodles, but have you ever considered fermented black beans? They're "black soybeans which have been cooked, salted and fermented, often with slivers of ginger, and this treatment turns them into flavor powerhouses. They smell somewhat like a good aged cheese, and surprise! They are absolutely filled with natural glutamates. They make whatever they are stir fried, stewed, steamed or simmered with taste amazing. I cannot praise them highly enough."