PDF documents you can download.
Act! is still the one!
http://act.com/media/en-us/docs/briefs/Act!ProductBrief.pdf
What’s New in Act! v16
http://act.com/media/en-us/docs/briefs/Whats-new-in-Act-v16.pdf
What was new in each version of Act!
http://www.act.com/media/en-us/docs/Act-Version-Comparison.pdf
Swiftpage Connect Email Marketing
http://act.com/media/en-us/docs/briefs/SageEmarketingforACTProductBrief.pdf
Act! 16 New Users’ Installation Guide
http://www.act.com/media/en-us/docs/documentation/Install-Guide.pdf