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New to IT or Cybersecurity?
Are you a complete beginner to the field of Information Technology or Cybersecurity? Or, perhaps you have a bit of experience, but are looking for a refresher of the fundamentals. Either way, I've put together a learning path of high quality and free resources that will help you cement a solid foundation.
In the interest of keeping this page tidy and focused on the free informational resources found below, I've moved the learning path to its own dedicated page.
Informational Resources
Systems Administration
Core Systems Concepts
- Storage
- CPU
- Memory
- Boot procedure
- System internals
- Core directories
- Filesystem hierarchy
- Windows Registry
- Event and audit logs
Shells and Terminals
This is a fantastic history lesson on the way humans have interacted with computer systems. It's a long read, but it is very educational and covers the primitive terminals with punch cards all the way to the current terminal emulators as we know them today.
A Guide to the Terminal, Console, and Shell
The terminal is the result of its history, from the telegram to our terminal...
Terminal Emulators
The terms console and terminal are used interchangeably to reference the software run by the user to emulate bygone physical terminals. Whether you choose to call it a terminal or a console, this piece of software presents to you the command-line interface via which your commands are passed to the shell.
GitHub - cdleon/awesome-terminals: Terminal Emulators
Terminal Emulators. Contribute to cdleon/awesome-terminals development by creating an account on GitHub.
Command Shells
After you're done reading the history of the terminal, you'll have a better understanding of what a shell is. For now, understand that the shell functions as an interpreter that receives your commands, translates and executes those commands, then returns the resulting output from the execution.
Hyperpolyglot Shell: Bash, Fish, Ksh, Tcsh, Zsh
A side-by-side reference of common commands and operations in bash, fish, ksh, tcsh, and zsh shells...
Bash Scripting
Scripting automates common tasks by coding a sequence of commands to be executed by the shell. Bash scripting is crucial for system administrators and developers to perform repetitive tasks efficiently.
Bash Scripting Tutorial for Beginners
A comprehensive guide to bash scripting with practical examples for beginners
PowerShell
PowerShell is Microsoft's task automation framework, consisting of a command-line shell and associated scripting language built on .NET. PowerShell's deep integration with Windows makes it an essential tool for Windows administration.
Getting Started with PowerShell
Learn the basics of PowerShell and how to use it for Windows administration
Networking
Understanding networking fundamentals is essential for any IT professional or cybersecurity specialist. Below are resources that cover the basics of networking, protocols, and network security.
OSI Model
The Open Systems Interconnection (OSI) model is a conceptual framework that standardizes the functions of a communication system into seven abstraction layers:
- Physical Layer - Transmission and reception of raw bit streams over a physical medium
- Data Link Layer - Node-to-node data transfer, error detection and correction
- Network Layer - Routing and forwarding, addressing, internetworking
- Transport Layer - End-to-end communication, segmentation, acknowledgments, multiplexing
- Session Layer - Managing communication sessions
- Presentation Layer - Data translation, encryption, compression
- Application Layer - High-level protocols, resource sharing, remote file access
TCP/IP Model
The TCP/IP model is a more practical implementation with four layers:
- Link Layer (Network Interface) - Physical addressing and media access
- Internet Layer - Logical addressing and routing (IP)
- Transport Layer - End-to-end communication (TCP, UDP)
- Application Layer - Network applications and services (HTTP, FTP, DNS, etc.)
Computer Networking: Principles, Protocols and Practice
A comprehensive open textbook on computer networking covering everything from the basics to advanced topics
Introduction to Computer Networks
An introduction to the principles and practice of computer networking
Security
Security resources to help you understand fundamental security principles, threat modeling, and defensive techniques.
Security Principles
- Confidentiality - Ensuring information is accessible only to authorized individuals
- Integrity - Maintaining the accuracy and consistency of data
- Availability - Ensuring information is accessible when needed
- Non-Repudiation - Preventing denial of actions performed
- Authentication - Verifying the identity of users or systems
- Authorization - Determining what actions users are allowed to perform
Common Security Concepts
- Defense in Depth - Multiple layers of security controls
- Principle of Least Privilege - Grant only necessary access
- Zero Trust - Never trust, always verify
- Risk Management - Identify, assess, and mitigate risks
OWASP Web Security Testing Guide
The Web Security Testing Guide is a comprehensive guide to testing the security of web applications
Linux Hardening Guide
A comprehensive guide to improving the security of your Linux server
Hack The Box
Online platform to test and advance your cybersecurity skills
TryHackMe
Learn cybersecurity through hands-on challenges
Cloud
Cloud computing resources to help you understand and navigate the major cloud platforms and technologies.
Service Models
- IaaS (Infrastructure as a Service) - Provides virtualized computing resources (e.g., AWS EC2, Azure VMs)
- PaaS (Platform as a Service) - Provides platform for developing and running applications (e.g., AWS Elastic Beanstalk, Azure App Service)
- SaaS (Software as a Service) - Delivers software applications over the internet (e.g., Office 365, Google Workspace)
- FaaS (Function as a Service) - Serverless computing (e.g., AWS Lambda, Azure Functions)
Deployment Models
- Public Cloud - Services offered over the public internet by third-party providers
- Private Cloud - Cloud infrastructure operated solely for a single organization
- Hybrid Cloud - Combination of public and private clouds
- Multi-Cloud - Using services from multiple cloud providers
- Community Cloud - Infrastructure shared by several organizations with common concerns
AWS Training and Certification
Free digital training on AWS services and solutions
Microsoft Learn: Azure
Free, online training to build your cloud skills with Azure
Google Cloud Training
Free courses to build your Google Cloud skills
Command Line Operations
Essential command line operations and tools for both Unix-like and Windows environments.
Popular Unix Shells
- Bash (Bourne Again SHell) - The default shell for most Linux distributions and macOS (until Catalina)
- Zsh (Z Shell) - Extended Bourne shell with improved features, now default on macOS
- Fish - User-friendly shell with syntax highlighting and autosuggestions
- Ksh (Korn Shell) - Compatible with Bash but with some unique features
- Tcsh - Enhanced version of the C shell with command-line editing capabilities
Shell Configurations
.bashrc/.bash_profile- Bash configuration files.zshrc- Zsh configuration file.profile- Login shell configuration.inputrc- Readline configuration
Common Tools
- Oh My Zsh - Framework for managing Zsh configuration
- Starship - Cross-shell prompt customization
- Tmux - Terminal multiplexer for multiple sessions
- Screen - Terminal window manager
# Install Oh My Zsh
sh -c "$(curl -fsSL https://raw.github.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"
# Basic tmux commands
tmux new -s mysession # Create new session
tmux attach -t mysession # Attach to session
The Art of Command Line
Master the command line, in one page
Bash Reference Manual
Official GNU Bash manual
PowerShell Documentation
Official Microsoft PowerShell documentation
Containerization & DevOps
Resources and information about containerization, orchestration, and the DevOps methodology.
Containers
- Docker - Platform for developing, shipping, and running applications in containers
- Container Images - Lightweight, standalone packages with everything needed to run an application
- Registries - Repositories for storing and distributing container images (Docker Hub, AWS ECR, etc.)
- Docker Compose - Tool for defining and running multi-container Docker applications
Container Orchestration
- Kubernetes - Open-source container orchestration system for automating deployment, scaling, and management
- Key Concepts: Pods, Deployments, Services, Namespaces, ConfigMaps, Secrets
- Managed Solutions: AWS EKS, Google GKE, Azure AKS
- K3s - Lightweight Kubernetes distribution for edge computing and IoT
Docker Documentation
Learn Docker and containerization from the official docs
Kubernetes Documentation
Learn about Kubernetes architecture and components
The DevOps Handbook
How to Create World-Class Agility, Reliability, & Security in Technology Organizations