Recently, I wrote a series of posts called The Ultimate Profile Auditing Guide. The purpose of the guide is to help you navigate viewing Profiles on a large scale through Excel as a means of running an audit on your Profiles. Below is the list of posts in the order that they go in.
This post guides you through the initial thought process behind the series and some uses cases of why auditing profiles may be important.
This post is designed for those who may be less familiar with all of the different ways that Salesforce handles security on a record and user basis.
This post walks through how you set up Pivot tables in Excel, as not everyone is familiar with the process.
This post contains all of the best goodies. It has the SOQL statements that can be modified to get exactly the data you are looking for out of Salesforce.
Lastly, this post takes the above posts and puts of the pieces together so you can see the process end to end.