Slack
Create a Slack Team: https://slack.com/create
Slack Onboarding Checklist: https://get.slack.help/hc/en-us/articles/217626328-Onboarding-checklist-...
Slack UI Cheat Sheet: https://get.slack.help/hc/en-us/articles/217626358-Cheat-sheet-for-basic...
Guides for Using Slack: https://get.slack.help/hc/en-us/categories/200111606-Using-Slack
Guides for Team Administration: https://get.slack.help/hc/en-us/categories/200122103-Team-Administration
Slack App Directory: https://slack.com/apps
Slack Pricing: https://slack.com/pricing
Trello
Trello tour - https://trello.com/tour
Primer/Get started Webinar - https://trello.com/webinars
Power-ups: http://help.trello.com/category/1006-power-ups
Trello Help - http://help.trello.com
Cost - https://trello.com/pricing
On-Demand Webinars:
Getting Started with Trello
Business Class 101
Essential Boards for Businesses
Better Boards For Team Collaboration
The Power-Ups Platform
HR Made Easy With Trello
Organizing for the Holidays with Trello