Honestly? If you are looking for online materials for learning history, then you might as well look for the good stuff. And to that end, it's worth finding actual history course lectures.

There are actually a bunch of free lectures available online through various institutions of higher education. For example, Yale University offers Open Yale Courses, for free. These are all filmed course lectures (from about 10-ish years ago), but come complete with the syllabus and links to the reading materials. I particularly recommend David Blight's Civil War and Reconstruction Era course.

Open University also has a series of free online courses available, including by such big names as Ian Kershaw.

I think one benefit to going to these kinds of sources is that while it may be very academic ... it's free! So try what interests you. You're also getting information from actual academic historians, as opposed to from tertiary sources that are filtering their work through another medium.

For American Revolution stuff I like The Journal of the American Revolution at www.allthingsliberty.com . Lots of good articles, reviews, podcasts with historians on the latest scholarship (there's a great one with Colin Calloway on Washington's Indian policy that goes along with his newest book). Articles are searchable by subject, and most are pretty short reads. Been very informative for me the last couple of years.

The best resource I've found (and been a part of) is the American Yawp project. American Yawp is a free, digital, open history textbook that was created with input from hundreds of professional historians. It also includes a primary source reader if you're looking to delve into some history documents. The project can be accessed at http://www.americanyawp.com/

Hi there anyone interested in recommending things to OP! While you might have a title to share, this is still a thread on /r/AskHistorians, and we still want the replies here to be to an /r/AskHistorians standard - presumably OP would have asked at /r/history or /r/askreddit if they wanted non-specialist opinion. So give us some indication why the thing you're recommending is valuable, trustworthy, or applicable! Posts that provide no context for why you're recommending a particular podcast/book/novel/documentary/etc, and which aren't backed up by a historian-level knowledge on the accuracy and stance of the piece, will be removed.