Are there lectures and lessons out there I can use for my class?
Yes! But there are many - almost too many to count! Check out these top resources (some are free and others require a membership). You can create your own account and upload your videos to most of these sites for free.

Website
Features
Examples
Ted-Ed
You can "Flip" the videos - use one of their videos and customize it for your students. You can add questions or context, then assign it to your students.
The infamous and ingenious Ho Chi Minh trail - describes the history and its usage during the Vietnam war
Khan Academy
Mostly math and science videos, but students can track their progress in a course and can earn badges. Also includes test prep, including SAT math.
After watching a lecture for measuring angles, students can practice measuring using a protractor.
SOPHIA
Earn Flipped Classroom and iPad Prepared Certifications (sponsored by Capella University). Some videos, some "packets". Offers college courses.
A tutorial on demonstrative adjectives in Spanish. A Google form is embedded for students to answer
TeacherTube
Teacher and Student made videos; note: you have to do some digging for good content
Check out this brief video on how heat travels.
SchoolTube
Teacher and student made videos
A short video about the phases of the moon - a kids version
BrainPOP
Free animated education videos with questions embedded during the video; you receive more videos with a paid subscription
Watch this free, featured video on the 13 colonies.