Here is a list of some of the most well known sites for good how to and DIY videos and guides. Most of the videos you'll find here are available for free. Although I have numbered the list, the numbers are not meant to imply a ranking:
1. Howcast.com, along with the specialty sites, Howcast for iPhone, Howcast for Android and Howcast for iPad was launched in 2008 with offices in New York City and San Francisco by a group of former Google employees. Howcast offers short how-to video and text guides. The videos are made by film students, recent grads, and up-and-coming filmmakers as part of the Howcast Emerging Filmmakers Program (EFP), which is partnered with film and television programs at Boston University, Chicago's Tribeca Flashpoint Media Arts Academy and Australia's Charles Sturt University. The site is available in English and Spanish.
2. VideoJug.com is a UK based multilingual site which has been offering professionally-produced expert and user generated how to videos and guides since 2006.
3. WonderHowTo.com is a community-developed website of how-to videos & articles from specialized creators, spanning a wide variety of categories and sub-categories. Founded in Santa Monica, CA in 2008, it also reports real time news events of all things DIY.
4. SuTree.com is an Israeli based knowledge community and an aggregator of instructional and educational videos. The site was created in 2006 and relies heavily on user-uploaded aggregation.
5. HowTo.tv is a website that hosts instructional, brand-sponsored videos. Headquartered in London, it was established in 2007.
6. Instructables.com, which has been around since 2005, specializes in user-created and uploaded DIY projects, which other users can comment on and rate for quality. The San Francisco company's origins were in the MIT Media Lab where the future founders of Squid Labs built places to share their projects and help others.
7. 5min.com is a syndication platform for professionally produced broadband instructional, knowledge and lifestyle videos. The New York based company was started in 2007.
8. Sclipo.com calls itself 'the world's largest platform of Online Campuses' and provides e-Learning, social networking and promotional applications for learning, teaching and collaborating. On addition to videos, papers, and audio files, there is also a virtual classroom application that allows participation in live classes, webinars and meetings. Founded in Barcelona, Spain in 2007 (then called Visuarios), it is available in English, Spanish, German and Russian.
9. HelpfulVideo.com is a Canadian website that promotes itself as a place where everyday people exchange videos about everyday knowledge and skills. Some of the videos are free and some are for sale. You can also sell your own videos through the site. It has been in operation since 2006.
10. SaberHacer.com provides how-to and educational videos by experts on a range of topics in both English and Spanish. Topics include Careers and Jobs, College Education, Personal Finance, Parenting and Family, Health, Citizenship, Computers, Internet and more. SaberHacer was founded in 2008 by former broadcast journalist Michele Ruiz as a resource for U.S. Hispanics. Headquarters are in Burbank, CA.
12. MonkeySee.com provides free access to a large collection of professionally-produced and user-generated how-to videos. All videos are created in HD. Owned by Knowlera Media, Great Falls, VA, which was started in 2010.
13. TVLesson.com is a community driven website with a library of from how-to videos and how-to articles.Founded in Brea, CA in 2008.
14. eHow.com has a virtual library of millions articles and videos as well as an on-line community for sharing experiences and providing real-life advice. This is the oldest site, having been launched in 2003. Maybe because of that, and the large volume of contenet, it is also probably the site that has received the most criticism, including accusations of being a content mill. Corporate headquarters located in Bellevue , WA.
15. TeacherTube.com is a YouTube type site for sharing instructional videos. The site is organized in the following categories: Videos, Docs, Audios, Photos, Groups, Classrooms and Collections. You can do a simple search, or search using a drop-down menu which offers choices among Curriculum, Content Area, Subject, Category and Skill. The Texas based site was founded in 2007.
And although its not a how to site, don't forget YouTube has many how to and DIY videos. Just do a search for whatever it is you are looking to learn.
Please feel free to add your own suggestions in the comment section below and to let me know of any feedback you have on the sites I've listed here, including reports of broken links.