Saylor Academy - Mathematics

Free, full-length math courses (Linear Algebra, Abstract Algebra, Real Analysis, etc.) with exams and certificates.

Manhattan Review Free GRE Resources

Free practice problems, diagnostic tests, and study tips from test prep experts.

Analytics Vidhya

Wide range of free tutorials, guides, and case studies on data analytics, machine learning, and business intelligence.

Google Data Analytics Certificate (Audit Free)

Comprehensive beginner-to-intermediate program covering spreadsheets, SQL, R, visualization, and analytics workflows; free in audit mode.

HackerRank SQL Domain

SQL challenges of varying difficulty levels with instant online feedback, great for structured practice.

Udemy

Udemy is a global learning platform offering self-paced courses in analytics, statistics, and decision modeling?ideal for those pursuing or preparing for a U.S. Army ORSA role.

Kaggle Learn R

Hands-on mini-courses for R programming, data visualization, and machine learning with interactive notebooks in the browser.

W3Schools Python

Step-by-step interactive lessons for Python basics, data structures, and functions, with hands-on coding snippets.

Quick-R (StatMethods)

Practical R tutorials focused on statistics, graphics, and data analysis, written in a straightforward, example-driven style.

LearnPython.org

Interactive, browser-based Python tutorials ranging from basic syntax to advanced modules.

Coursera - R Programming (Audit Free)

Johns Hopkins University?s R Programming course (part of the Data Science Specialization), free in audit mode with videos and quizzes.

Nexus: A Brief History of Information Networks

Brian Christian

A sweeping narrative on the evolution and impact of global information networks

Kaplan GRE Free Resources

Free practice tests, sample questions, and study materials from Kaplan.

Power BI Community

Official Power BI community forum where users can ask questions, share solutions, and browse a large knowledge base of solved problems.

PAXsims (Conflict Simulation & Wargaming)

Long-running blog on serious games and wargaming for policy, education, and analysis with news, methods, and reviews.

King?s Wargaming Network

Academic network advancing theory and application of wargaming for research and teaching within Security Studies.

Kaggle Learn Python

Hands-on mini-courses for Python and data science, with notebooks you can run in the browser for immediate practice.

Kasper On BI

Blog by a Microsoft program manager sharing deep-dive explanations of Power BI features and integrations with Azure and Excel.

EDX ? Analyzing and Visualizing Data with Power BI (Audit Free)

University of Illinois & Microsoft course teaching Power BI for analytics and reporting, free in audit mode.

Real Python (Free Articles)

In-depth tutorials, explanations, and code examples for beginners to advanced Python developers, with a mix of free and premium content.