W3Schools Python
Step-by-step interactive lessons for Python basics, data structures, and functions, with hands-on coding snippets.
PAXsims (Conflict Simulation & Wargaming)
Long-running blog on serious games and wargaming for policy, education, and analysis with news, methods, and reviews.
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.
Princeton Review GRE Practice
Free practice test access, strategy sessions, and sample GRE questions.
CS50?s Introduction to Python
Harvard?s free course introducing programming using Python, with video lectures, notes, and problem sets.
Mode Analytics SQL & Analytics Tutorials
Hands-on tutorials that blend SQL queries with practical data analysis tasks for business analysts.
CRAN R Project Documentation
Official manuals, FAQs, and reference documentation for the R language from the Comprehensive R Archive Network.
DataCamp
DataCamp is an online learning platform that specializes in data science, analytics, and artificial intelligence, offering interactive courses in Python, SQL, R, and other key technologies. Learners can build practical skills through hands-on coding exercises, real-world projects, and guided career tracks?all accessible from a browser at their own pace.
StatQuest with Josh Starmer (YouTube)
Clear and approachable explanations of statistics and data analysis, breaking down complex concepts into simple steps.
OpenIntro Statistics
Free, open-source statistics textbook with R labs and applied data analysis examples.
edX - Data Analysis for Life Sciences
Harvard's free online courses teaching statistics, inference, modeling, and machine learning in the context of data science.
SQL Shack ? Power BI
Collection of practical Power BI tutorials and tips, especially useful for SQL Server professionals integrating BI dashboards.
HackerRank SQL Domain
SQL challenges of varying difficulty levels with instant online feedback, great for structured practice.
Test Guide - GRE Practice
Large collection of free online GRE practice tests and section-specific drills.
Marine Corps Warfighting Lab ? Wargaming Division
USMC wargaming division supporting concept development and force design through iterative gaming and analysis.
CrunchPrep GRE Blog
Guides and strategies for GRE preparation including word lists, essay templates, and quantitative shortcuts.
Kaggle Learn Python
Hands-on mini-courses for Python and data science, with notebooks you can run in the browser for immediate practice.
R for Data Science (Hadley Wickham & Garrett Grolemund)
A free online book teaching R through the tidyverse approach, covering data wrangling, visualization, and modeling.
Google Data Analytics Certificate (Audit Free)
Comprehensive beginner-to-intermediate program covering spreadsheets, SQL, R, visualization, and analytics workflows; free in audit mode.
LeetCode SQL Problems
Collection of SQL coding challenges to practice writing queries, often used in interview preparation.