Check this profile to get an introduction to Marshall McLuhan, his thought, and his works on media. This provides a starting point to understand Media Ecology as a key field for any effective critical cultural analysis.
Also, this quote pulled from the profile points to the handoff that took place from Marshall to his son Eric, whose work continues today, and also to a core analytical tool (the 4 Laws) you should include in your arsenal:
As the media popularized his ideas, McLuhan continued his work at the Centre for Culture and Technology, collaborating with eldest son Eric McLuhan to develop a synthesis of his ideas. Together they published a number of articles and books and attempted to articulate what they had began to refer to as the “4 Laws of Media”: every technology
(1) amplifies part of our culture,
(2) obsolesces aspects previously amplified,
(3) retrieves elements previously obsolesced, and
(4) eventually reverses or “flips” into something else entirely.