أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
It is hard to reckon the "best resource" for anything. 'What is best', it totally depends upon one's own needs and plans.
Do little research according your plans, interest and practical real world application.
try https://www.coursera.org/courses.
