Many of the tips I have been reading regarding saving money suggest keeping the infamous "price journal". I know when I started trying to save money, trips to the grocery store were different, mostly because I had no idea what was a "normal" price for a typical item. I had no idea what was expensive and what was a good deal. Especially when you come into trying to start saving money out of the blue and/or do not have a lot of experience cooking, this is good habit to keep up with. The premise of the idea is to basically keep a journal where you record what things cost that you buy on a consistent basis. Be sure to be very specific when recording these items, like the brand and size of the product. That way, when things go on sale at the grocery store, you will know a) how much you are saving, b) if the sale is worth taking up on, and c) how much to stock up on.
Keeping a journal like this will also likely make you more aware of what things cost in general. The experience of writing down what prices of things actually cost bring a bigger realization of where your money is going, and if it is really worth it. A journal is incredibly cheap to pick up, especially with school supply sales going on right now, it can be anything that fits your lifestyle, which is important to note since it should be traveling with you for grocery trips. Borders and other book stores typically sell cheap $2 journals as well, if you would like something more fancy, go for it.