Cold Email: How do I learn everything there is to know about SendGrid? (apart from their official tutorials, that is)

Hello,

I have signed up to use SendGrid for work, to send out marketing emails. Where can I learn everything there is to know about it (apart from their official tutorials). Sometimes there are some resources that are "must-reads" to know the nitty-gritty of an operation, and those are the sort of resources I'm looking to know more about.

Thanks in advance!