• Free online textbook introducing new users to the basics of spreadsheets and is appropriate for learners who have not used Excel before

• A basic introduction to spreadsheets and how they work

• Part of the Libre Office suite, a free and open source spreadsheet application 

• Tutorial looking at 6 areas forming the core of basic Excel skills. Site has lots of useful resources

Contextures Excel Resources

• Hundreds of Excel tutorials, along with step-by-step training videos, and tons of sample Excel workbooks that you can download

Create Your First Excel Macro: A Step-by-Step Guide for Beginners

• YouTube tutorial on creating macros

Excel Practice Online

• Practice And learn Excel online for free

ExcelFunctions

• This website has been created to provide help with Excel functions and formulas

ExcelJet

• Learn Excel with clear examples and bite-sized videos

GCFGlobal: Google Sheets

• In this free tutorial, learn how to use the powerful tools in Google Sheets for organizing, visualizing, and calculating data in a spreadsheet.

Get Started With Google Sheets

• Google support pages

Getting Started with Calc

• Book chapter from Getting Started With Libre Office

Google Sheets

• Google's free, online version of Excel

Keyboard Shortcuts in Excel

• This article describes the keyboard shortcuts, function keys, and some other common shortcut keys in Excel for Windows.

LibreOffice Calc Tutorials

• This page contains LibreOffice Calc Tutorial(s) grouped based on the learning curve

Spreadsheets: Terminology

• Short glossary of terms used in spreadsheets

W3Schools Excel Tutorial

• Good tutorial from a well-established tutorial provider

W3Schools Google Sheets Tutorial

• Tutorial with practical examples to give the user a better understanding of the concepts

What Is a Spreadsheet?

• Detailed Microsoft page on spreadsheets

What Are Spreadsheets and How Do They Work?

• Introduction to spreadsheets, what they're used for and their pros and cons