You should definitely check out
Coursera and
Udacity. These sites provide access to short courses developed by major universities around the world in a wide range of subjects. The materials are usually based on the course materials presented to their regular students, but adapted where necessary for online presentation. There's also
EdXOnline, which hosts online material from several major universities, but I haven't really looked at this myself.
On
Coursera, each course is usually 5 to 10 weeks, with regular weekly course work that you may have to submit for automated marking or possibly for assessment by your peers online, depending on the subject. As there may be 50,000 students or more taking a single course, there is not much direct interaction with the teaching staff, but there are usually online forums etc where you can ask questions and share ideas.
Udacity takes a very similar approach, but some of their courses are designed so you can work through them at your own speed, rather than to a particular schedule.
You cannot get university credit for these courses (although there are a couple of US universities looking at this), but many courses offer a "statement of accomplishment" or similar certificate. In any case, the quality of the materials and teaching is very high and the courses give you access to subjects and expert teaching that you would normally have to pay a lot of money for in a conventional university, so the real value is the content, not the certificate.
Both sites offer a range of courses in computer science taught by real experts (e.g. I recently completed the Coursera course on functional programming with Scala, presented by Martin Odersky - the guy who invented the Scala programming language). Udacity has a much smaller range of courses currently, but many of them look very interesting, while Coursera has a much wider range, including many non-CS courses as well.
One warning: Once you start digging into this stuff, you'll keep finding more and more courses you want to take - you may not see your family again for months!