GEDmatch.com is a volunteer-run free website providing additional tools for people who have already tested their autosomal DNA at one of the main genetic genealogy testing companies: 23andMe, AncestryDNA, Family Tree DNA (their Family Finder test), Living DNA and MyHeritage. Users create a free account at GEDmatch, then download their DNA raw data from their own account at the testing company and upload that raw data to GEDmatch. This handy guide (8 page booklet), covers the basics from file uploads, to "your DNA resources" (where all the kits you manage are), to analysing your data, and includes a glossary with a bunch of DNA related terminology.
There is also a learn more section, and further reading suggestions.
8 page A4 booklet, b&w and colour photos
Kerry Farmer, Unlock the Past handy guide, 2019