Pathmark, Shoprite, Acme, A&P, Stop and Shop
This is the location that first comes to my mind when I think about raiding a store. It has the benefit of being smaller in size than most wholesale locations, therefore making it easier to isolate any threat that may be lurking within. This also helps to make the duration of your stay much shorter. You can find a huge variety of food, hygienic supplies, and medical supplies at this type of location.
A grocery store is not going to carry much for the long term. They unfortunately carry a lot of goods that expire. They also do not have as much stock as some larger stores and if there are many survivors there probably will not be anything useful left after a short period of time. Grocery stores or supermarkets do not carry the same diversity of goods as wholesale stores. At least around metropolitan areas, most lack any type of firearms and have a very limited hardware section. As far as the weapons you may find in a grocery store, you may be limited to kitchenware and cleaning supplies. I would always stop at your local hardware store for a quick weapons fix.
What do I take?
The first thing I would go for in a grocery store is their medical supplies. You should always have the necessary supplies for any situation or anything that could lead to your demise. Just grab everything from Advil to Preparation H. You don't want a sore ass when fighting the undead. Stock up on bandages, gauze and everything you need to deal with injuries. You always need to be aware of exposed wounds or anything that could lead to an accidental infection.
||The Pharmacy Aisle
While you are in that department grab any hygienic items you may need. Being dirty just leads to you getting sick and making you more susceptible to getting your ass beat by zombies. For those of you who don't know or who don't frequent these products this pertains to soap, shampoo and even deodorant, it just makes traveling with a group that much harder.
Finally the easiest thing to find at a supermarket is food. This is where time comes into play. If the outbreak is recent you can probably find a lot of fresh fruit and vegetables, bread, milk, eggs, anything for your healthy diet. If it is a couple months into your survival, you would have already figured out that this type of stuff is not going be edible any more. Try and take as much food as you can that you know is going to last. Canned food is always number one, of course.
Quick Check, Wawa, 7-Eleven, Sheetz, Walgreens
I would say 98% of the time these are the places you would want to go to use "The Alternate Method." Convenience stores are typically very small. In a serious outbreak they would be completely depleted of anything useful in less than 3 weeks.
What do I take?
This is the place to stop for a quick sugar high. The majority of the products in these stores are snack foods that are very high in sugar. They are great to pep up a tired "caravan on the go". You may find a small section with flashlights, razors, and maybe even a pocketknife. Not anything much more useful than that.
So hopefully what you pull away from this guide is to keep things short and always have an escape plan. The longer you screw around while raiding, the more likely it is you'll find yourself in trouble. There's a reason for the saying "the quick and the dead." You can never be too safe, so watch your backs out there.