These directions show you how to create a profile with access to Sales Insight while removing access for your other profiles. These instructions assume you've already installed the Sales Insight AppExchange package.
Next, pick a profile to clone and give the new profile a name. Click Save when you're done:
Clone your layout of choice and give the layout an appropriate name like Sales Insight Layout. Click Save when you're done.
Here are some other places where Sales Insight items could appear. You'll have to remove them outright since you can't use Profiles to limit access to them: