Can someone tell me where I can find Analytics documentation/an Analytics how-to guide?

This might be the quickest link: https://www.tessituranetwork.com/Help_System_v151/Content/Tessitura%20Analytics/Intro%20and%20Overview/Introduction.htm

And you can click "Open topic with navigation" to restore the full documentation view.

Alternately, clicking the little "person" icon in the top right-hand corner of the Analytics module also gives a Documentation link:

Thanks, Brian!