edX - Data Analysis for Life Sciences

Harvard's free online courses teaching statistics, inference, modeling, and machine learning in the context of data science.

Project Euler

Hundreds of challenging computational math problems that build problem-solving and programming skills.

Analytics Vidhya

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

Power BI Guided Learning (Microsoft)

Step-by-step tutorials directly from Microsoft, teaching data connection, modeling, visualization, and publishing dashboards.

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.

MOOC.fi - Introduction to Data Analysis with Python

Free course from University of Helsinki teaching data analysis workflows with Python and Pandas.

Stack Overflow - R Tag

A huge developer community answering detailed questions about R, packages, and applied statistics.

Microsoft Learn - Data Analysis

Free learning paths covering data analysis basics and Power BI dashboards directly from Microsoft.

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.

Coursera

Offers beginner-friendly courses from top institutions like IBM and Duke. You can audit many courses for free, including topics like Excel, SQL, Python, and data visualization.

PAXsims (Conflict Simulation & Wargaming)

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

Khan Academy - Intro to SQL

Beginner-friendly course teaching SQL fundamentals with practice problems and video explanations.

R for Data Science (Hadley Wickham & Garrett Grolemund)

A free online book teaching R through the tidyverse approach, covering data wrangling, visualization, and modeling.

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.

Designing Machine Learning Systems

Chip Huyen

A practical blueprint for building production-ready ML systems with scalability and reliability

The Carpentries - Data Carpentry

Community-driven lessons for researchers covering data organization, cleaning, visualization, and analysis in R, Python, and SQL.

ModernDive: Statistical Inference via Data Science

Free online textbook teaching statistical inference and regression using R and tidyverse methods.

LeetCode SQL Problems

Collection of SQL coding challenges to practice writing queries, often used in interview preparation.

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.

FlowingData

Visualization-focused tutorials and guides on analyzing and presenting data effectively.