Data.
The majority of the raw data I analyze in my articles comes from MoneyPuck.com. They have downloadable CSV files that have data including over 100 variables on every skater, goaltender, line/defensive pairing, and team for all seasons from 2008-2009 until now. The data is available at both an individual player level and team level, as well as at a game by game level and a full season level. There is also a series of CSV files that contain data on every shot taken during both the regular season and the playoffs since the start of the 2007-2008 season, separated into CSV files based on the season and catalogued in the order in which the shots occurred. Additionally, they have biographical information on every NHL player since 2007.