I did not take any classes online but I did take classes at Neighborhood Housing Services NHS and Housing Preservation Development HPD in NYC. Both were free, look to see if you have these in your city.
The office of Adult and Continuing Education in NYC also offers free courses on electrical, welding, carpentry, plumbing, solar install, a/c and refrigeration, boiler maintenance and building maintenance. I took webdesign from them so I cannot account for the other courses.
See if they offer this where you are.
http://www.youblisher.com/p/1045827-Office-Of-Adul...
I preferred NHS cause the teacher was nicer and it was more hands on. I put up studs, laid down tiles, changed locks, did plumbing. They showed me electrical and welding but I did not grasp it to well.
http://www.nhsnyc.org/en/?option=com_eventlist&vie...
The online courses are not as comprehensive
http://www.nyc.gov/html/hpd/html/buyers/online-dig...
Lastly there is youtube.