Both of those help articles are good sources, but they are either missing links to important help articles or also include links to administration help articles. Below is an extrack from the welcome email that we send our new Marketo users.
Marketo Sales Insight Overview, a short 5 minute presentation on the features/functionality
Day in the Life of a Sales Rep (passcode: insight), get a real-life salesperson's perspective on "How I use Sales Insight?"
Sales Insight Guide for Sales – an illustrated review of the features and capabilities of the Sales Insight section in Lead and Contact records and the Marketo Sales Insight dashboard tab.
Also check out the following help articles for using the email and other features in Sales insight and its Outlook Add-in.
I am curious to find out if such a document exist. I am in the process of creating documentation and training resources for our sales team. Right now, it has been a mixture of what you can find in the 'help for this page' link while in the Marketo tab in SFDC and some information/screenshots from the Community deep dive section.
The key is to make the information short and easy to follow in a PowerPoint deck. Video seems to be the best approach, the Day in a life is quite helpful along with the 5 min overview. Also, the links in the section labeled Access the MSI Fundamentals recorded modules: in this Community article http://community.marketo.com/MarketoArticle?id=kA050000000KyuWCAS is accessible to anyone.