If someone were to try to roast their own beans (in small batches) for the first time, what are the everyday/common household tools that works for this and how did you do it?
The most important thing for roasting is the heat source. You cannot roast without heat and the type of heat source will influence the result of the roast. For home roasting, I can think of two obvious heat sources:
An oven, though this requires some additional material. To use this method you need something to hold the coffee. You'd want the heat to be distributed evenly, but that's quite hard unless you have something so the beans move around while roasting. I've tried home roasting with stainless steel mesh dishes so the heat can move around the beans with the fan providing the most air circulation my oven can handle. Even then the beans don't roast evenly with those at the edge of the tray browning much faster compared to the ones in the center.
A popcorn machine. The benefits of a popcorn maker are that the beans get agitated and they generally provide enough heat. Downsides of this option are that you have little control, you can only roast small batches and the device may overheat (popcorn takes less time to make than roasting beans).
A pan on the stove. The benefits are that you can agitate the beans by stirring and you can control the speed of the roast by dialing the heat. The downsides are that you will have to stir throughout the roast so it all darkens evenly.
Another option would be to use a dedicated home coffee roasting machine, but those tend to be expensive and they're not really everyday tools. Whichever of these methods you use, there will be some or even a lot of smoke production (depending on how dark you roast). So you probably want to think about that as well, maybe by roasting outside or having active ventilation.
As for how it's done, all methods are pretty much the same. You heat the beans, you provide as much agitation throughout the process so the beans heat evenly. You know when they're done based on visual and audio queues. Per the overview on Wikipedia, different roast levels correspond to the beans' internal temperature. As the beans roast they get darker (see the pictures on Wikipedia) and at some stages you will hear a crack. When home roasting, these cracks may continues for a few minutes as the beans don't always roast evenly, just something to keep in mind. See also How to judge time between cracks when roasting on this site.
Warning: don't roast indoors. It stinks. Its a complete mystery how something that tastes so good can stink so bad when it's cooking.
Hot Air Pop Corn popper. Close, but no cigar. There are some very good "fluidized bed" roasters that look like Pop Corn poppers. But the Walmart Corn Poppers just don't cut it. They are not hot enough, so they dry out the beans without ever roasting them. if you are handy, you can get inside and short out the thermostat switch. This may work, or it may overheat the housing and produce a puddle of melted plastic. Don't ask how I know.
Oven: In my experience, the oven does a poor job because there is no agitation. Beans get black on one side and stay raw on the other. If you open the door often enough to do a good job agitating, the oven can't stay hot.
Stove-top frying pan, like a Jiffy Pop. This is a real minimalist approach, but it allows you to agitated continuously. Better than oven.
Best method: propane BBQ with rotisserie basket. Baskets are made specifically for roasting coffee. They are $23 on Amazon. Get the BBQ dang hot 425*F before you put the beans in. You'll need a digital thermometer and timer to maintain the temperature correctly. Beans are fussy about time and temperature.