Reading about the Tanenbaum-Torvalds debates:

• The classic debates/flamefest (And note the comment by Ken Thompson, one of the two creators of Unix!)
• More from Tanenbaum. Focus on the sections "Clearing up Some Misconceptions" and "Microkernels Revisited". Especially "Microkernels Revisisted".
• Linux is bloated, per Linus Torvalds