Software

Photoshop

​Adobe Basic Photoshop Tutorials
Understanding Layers - Learn how to use layers in the Layers panel, resize the contents of a layer, add images to a layered file, and work with a background layer in Adobe Photoshop. Five videos with sample images files to practice with.
https://helpx.adobe.com/uk/photoshop/how-to/ps-layers-basics.html 

Filters & Plug-ins
https://www.websiteplanet.com/blog/best-photoshop-plugins-filters/​

Guru99
https://www.guru99.com/photoshop-tutorials.html
Photoshop Tutorials 

Photoshop Essentials            
www.photoshopessentials.com
Photoshop Tutorials ​​​

​Clive Haynes                          
www.crhfoto.co.uk
Photoshop Tutorials

Lightroom

Tutorials on the latest versions of Adobe Lightroom.

Here's a shortcut cheat sheet for Lightroom and Photoshop - https://makeawebsitehub.com/adobe-cc-photographers-cheat-sheet/

And here's probably the best digital photography education site on the internet! - https://www.creativelive.com/photography

​Tutorials
http://photoshopcafe.com/tutorials/lightroom
 
Keyboard shortcuts  
Ctrl / OR
https://helpx.adobe.com/lightroom/help/keyboard-shortcuts.html
 
Free online book
http://lightroomkillertips.com/how-do-i/book/how-do-i-do-that-in-lightroom/how-to-get-your-images-into-lightroom/ 
 
Scott Kelby - Lightroom videos
http://kelbytv.com/thelightroomshow/