It probably isn't necessary for you to raise live food year round unless your are a die-hard hobbyist and you have fish that refuse to eat anything else. But you should be able to get through the warm months of the year feeding live food to your fish without much difficulty. I generally feed processed foods to my fish over the cold months, supplementing with newly hatched brine shrimp and frozen food. When it gets warm enough, I will go outside and start numerous cultures of mosquito larvae, brine shrimp, and daphnia. My fish will get live food supplemented with occasional processed flake foods until the end of the season.
Earthworms can be cultured indoors, in a large wooden box in a cold basement, year round.
Earthworms can survive for several days submerged in water in your refrigerator, which allows most of the soil in their gut to pass through their system, so that you won't dirty your tanks as much. Apparently, they find each other and don't know when to quit breeding. Probably any species of minnow that can survive in a garden pond would work just as well, but the rosies are nice because they are visible even in murky conditions. The normal fatheads are not normally visible, but at least the males change in appearance during mating, and almost act like cichlids. These fish are available from pet and bait stores in the Northeast U.S., but I have no idea where else they are available.