For online educational video resources (and clips of people falling over) you can’t beat YouTube. I know there are lots of other sources like Vimeo, TeacherTube and so on but this post is unapologetically YouTube biased.
Of course, the easiest way to find a video on a particular topic is to put keywords into the search field. Once you have found one appropriate video, this will often lead to others, as using the sidebars and checking other videos uploaded by that user are also useful search techniques. Beyond that, there are channels that show the videos of particular organisations and websites dedicated to connecting you with videos on particular topics.
Using the search field
You can conduct a keyword search of the titles and descriptions of videos on YouTube by putting the keywords into the search field (arrowed above). Like many search fields, this has been set up so that you can search for exact terms by putting your terms in inverted commas (e.g. “the solar system”), which will drastically reduce the number of results.
You cannot use the search field to search for a user. If you want to find videos by a specific user, put their name at the end of the URL after a backslash (e.g. www.youtube.com/aitkenonline).
Other ways to find videos
Once you have found a video, YouTube makes suggestions of other videos that might also be appropriate. These videos appear on the right-hand side of the screen (framed above).
You can also see other videos that have been uploaded by the user by using the method above or clicking on their username, which appears in blue just below the video.
Next to the search button is the Browse link. This takes you to the All Categories page. Clicking on the Categories button next to the All Categories heading will expand the categories menu. You can waste months drilling down into the different categories and finding distraction after fascinating distraction. Here is the link to the education category.
Videos of different organisations can be viewed through their channel. These too are accessed by putting the username at the end of the URL (e.g. http://www.youtube.com/user/MontyPython). Organisations advertise their channels on their own websites but there is also a list of education related channels here. Beware though, some of these channels, like the BBC channel, are not available in Australia.
There are loads of websites (blogs mainly) that aggregate videos about a given topic. One such blog is Open Culture. These work by the blogger selecting videos from YouTube and imbedding them in the post. If you know of any that are relevant to your subject, please let me know about them in the comments below.
If you want to go into the issue in more detail, YouTube have created a page especially for teachers. Check it out!