- Learn Python the Hard Way
- Python Code Academy
- Kirk Byer's Python for Network Engineers
- Learn Python
- Online Python Compiler
- Linux Foundation
- Introduction to Linux - Edx
- Linux Survival
- Beginners Guide to Linux
- Linux Fundamentals
- Linux Academy (Thanks, JB Poplawski)
- Google Cloud Training
- Microsoft Cloud Training
- AWS Training
- Acloud.guru (Special thanks to JD Murray)
Misc Microsoft, Cisco, Security, Vmware, etc free or near-free providers
- Microsoft Virtual Academy - Lots of free training for IT pros, developers, data pros, and students (same link as above)
- Virtual Training Company - Tons of low-cost training for $20/month
- Vmware Education - There's a lot of free resources here if you want to get your feet wet in Vmware knowledge
- Lynda - $20 a month to a huge library of courseware
- Udemy - GREAT content for pretty low prices. You'll often see video sets go for sale for $10-15 at select points of the year. There's training for every certification under the sun here and with many well-known trainers like JP Cedeno, Jason Lunde, Chris Bryant, and more.
- Free CCNA Course
- Free CCNA Book
- Routergods Youtube Channel - Hundreds of free labbing and networking videos
- Internetworking Technology Handbook
- Cisco Service Provider Training Youtube Playlist - 200+ free videos
- ACI for Network Engineers Free Training videos
- Cisco Data Center Training Youtube Playlist
- Cisco Advanced Security in ACI Playlist
- Labminutes ISE Training
- Labminutes Firepower Training
- Labminutes Route and Switch Training
- Labminutes Service Provider Training
- Labminutes Wireless Training
- Packetpusher's Virtual Toolbox - Thanks to Jeffrey Sicuranza for this!
- GNS3 Academy - Thanks to Jeffrey Sicuranze for this!
- IPSpace.net - Great blog and resource by Ivan Pepelnjak. Thanks to Jeffrey Sicuranza for having me add this in here!
- vBrownbag - Thanks Matt W!
- Vmware HoL - Stands for Hands On Labs. One of the AWESOME resources that Vmware provides for free
- Cisco DCloud - Stands for "Demo Cloud." With a free Cisco login, you can access a large variety of labs
- GNS3 - Great free emulator that lets you lab up Cisco and other resources
- GNS3 Vault - Collection of free GNS3 labs to help you master the technologies and troubleshoot
- Cisco Devnet Sandbox - Play with Firepower, ACI, Collaboration, and many other technologies for free
- Microsoft Hands On Labs
- AWS Free Tier
- Traffic Generating labs - Thank you, Srivats P
- Packet Tracer Labs - Thank you, Frederik Ferrell
- Free Packet Tracer download from Cisco - Thank you Frederik Ferrell
That's just the quick list I pulled from some of my bookmarks. Have fun and happy learning!