pickSaaS - Hundreds of SaaS products, analyzed.
Product School - The global leader in product management training
SaaS 1000 - Free exportable list of the fastest growing SaaS companies
The Product Folks - A volunteer-led community of product managers and makers
Inside SaaS Sales - 1000+ sales emails and voicemails from top SaaS companies
The Product Management guide - A book on how to create and ship products that people love