Math StackExchange
A global community where advanced math students and professionals ask and answer detailed mathematics questions, from abstract algebra to applied math.
W3Schools Python
Step-by-step interactive lessons for Python basics, data structures, and functions, with hands-on coding snippets.
CrunchPrep GRE Blog
Guides and strategies for GRE preparation including word lists, essay templates, and quantitative shortcuts.
PAXsims (Conflict Simulation & Wargaming)
Long-running blog on serious games and wargaming for policy, education, and analysis with news, methods, and reviews.
SQL Shack ? Power BI
Collection of practical Power BI tutorials and tips, especially useful for SQL Server professionals integrating BI dashboards.
Power BI Community
Official Power BI community forum where users can ask questions, share solutions, and browse a large knowledge base of solved problems.
Kaggle Learn R
Hands-on mini-courses for R programming, data visualization, and machine learning with interactive notebooks in the browser.
The AI-Driven Leader
Erik R. Peterson
A guide to leveraging AI for smarter decision-making and leadership strategies
Manhattan Prep GRE Resources
Free GRE study materials, strategy guides, and practice question sets.
Python.org Official Tutorial
The official Python tutorial covering core concepts, syntax, and standard library basics directly from the maintainers.
Google Data Analytics Certificate (Audit Free)
Comprehensive beginner-to-intermediate program covering spreadsheets, SQL, R, visualization, and analytics workflows; free in audit mode.
Saylor Academy - Mathematics
Free, full-length math courses (Linear Algebra, Abstract Algebra, Real Analysis, etc.) with exams and certificates.
Princeton Review GRE Practice
Free practice test access, strategy sessions, and sample GRE questions.
Magoosh GRE Blog
Hundreds of free articles, study guides, vocabulary lists, and strategies for GRE verbal, quant, and writing.
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.
Harvard Business School Online - Data Science Ready (Free Modules)
Intro modules teaching how analytics applies to business decisions, tailored for managers and analysts.
MOOC.fi - Introduction to Data Analysis with Python
Free course from University of Helsinki teaching data analysis workflows with Python and Pandas.
Marine Corps Warfighting Lab ? Wargaming Division
USMC wargaming division supporting concept development and force design through iterative gaming and analysis.
LeetCode SQL Problems
Collection of SQL coding challenges to practice writing queries, often used in interview preparation.