These days, Black Friday isn’t so much a single-day shopping holiday as it is an ever-expanding, monthslong event that often begins as early as October. The 24-hour deal blitz that once was the focus of newspaper headlines and mobs outside of stores is no more, which makes knowing when and where you should be spending your cash all the more confusing.

Luckily, we’re here to help. Over the next month or so, we’ll be poring through scores of presale spreadsheets and thousands upon…