New to ExpressionEngine? Start here. The materials and courses below will be the first thing(s) you'll want to work with you. This will get you up to speed on EE CMS.
Getting Started with ExpressionEngine Video Course|https://u.expressionengine.com/course/getting-started-with-expressionengine-video-course|Getting Started Project Repo|https://github.com/dougblackjr/learn-ee|Introduction to Building an ExpressionEngine Site|https://u.expressionengine.com/course/introduction-to-building-an-expressionengine-site ResourcesBelow are some links for Further Learning. You'll want to bookmark the Documentation link, you'll be using this a lot.
ExpressionEngine University|https://u.expressionengine.com/|ExpressionEngine Documentation|https://docs.expressionengine.com/latest/index.html OMGDeploy Build ProcessOnce you're comfortable with ExpressionEngine, it's time to get familiar with the OMGDeploy Build Process. There are videos and text for each stop by someone who's obviously a really confident person and has a really good speaking voice. So sit back, relax, and enjoy some sweet, sweet dulcet tones. It may just be the longest 2+ hours of you life.
Add-On DevelopmentAs you get more advanced and if you're familiar with PHP, you'll want to get into EE Add-On development. There's currently not a great process for this. The Documentation is serviceable but currently not comprehensive. You'll want to review the documentation and then start digging into existing add-ons and use them as a guide. The Add-on Builder is a cool tool for getting a new add-on started quickly. Hopefully more will be added here in the future.
EE Add-on Development Documentation|https://docs.expressionengine.com/latest/development/addon-setup-php-file.html|EE Add-on Builder|https://ee-addon-generator.triplenerdscore.xyz/