General Sites Relevant to Both Editions

Machiavelli Edition Summary
Machiavelli playing aids and info
Web-grognards links

Avalon Hill's Machiavelli, 1st Edition,1980

Game Reviews

Miscellaneous
Towards a Machiavelli Hall of Fame by Neil Barr

PBEM Sites
Machiavelli (1st Ed.) PBEM Game Page by Alan Poulter (Web Grognards)

Playing Aids
Machiavelli disaster table statistics  by Jon Ashman  (see middle of page)

Rules and Components

Strategy Guides

Variants/Scenarios
Mach I: Scenario Selection by Pietro Cremona (Web Grognards)

Avalon Hill's Machiavelli, 2nd Edition, 1995

Game Reviews
Machiavelli: A Primer for Diplomacy Players by Chris Hassler
Review by Richard Irving (Web Grognards)
Skirmisher Review
Summary of 2nd ed. by Rick Bynaker

PBEM Sites

Playing Aids
Differences Between 1st and 2nd Editions by Alan Poulter (Web Grognards)

Rules and Components
AH Correspondence with Rick Bynaker: Rules Clarifications
Official Clarifications and Errata (Dec. 3, 1997) (Web Grognards)

Strategy Guides

Variants
Variant Rules and Clarificiations by Risto (Includes a variant with Genoa as a major power)