You can also mail surveys to homes and businesses, or visit them in person, through this method. A sample of locations, be it homes or offices, can be gotten by first choosing areas at random, then blocks at random, then homes on those blocks at random. You could roll dice to determine which locations are picked. All this keeps personal opinions out of the research. You can do surveys with randomly chosen email addresses provided those in the study have given their permission to be contacted.
Most research is based on simple statistics.
No higher math is required. You can do just about everything with a simple calculator and advice from your junior high-aged child. If you want further information about scientific sampling and the statistics you can perform on your sample results, please consult one of the great many books on research. It's a subject that has remained largely unchanged for the past 50 years, so an old tattered volume in the used book store or at the public library will do just fine. Make sure your questions are clear and easily understood.