I just can't ignore some subjects here and have to touch them just a bit. One of those is for sure huge raise in MOOC in recents times (which stands for massive open online course).
There are many platforms right now that offer different types of online courses from free to paid ones, from beginners video tutorials to full-scale high class Universities courses.
I won't mention them all, instead I will only provide this link, which is place to find Top 50 Sites to Get Educated for Free.
I will however say that me personaly have used Coursera to learn Python, some Astrobiology and Sustainability :) and my experience is positive every step of the way. If you are in pursuit for knowledge Coursera is great, however if you need certifications, try some other place (for now, but it seems like that will change in the future). Coursera also won Best New Startup Of 2012.
Since I'm always hungry for more, my next project will be Diploma in Multimedia Development on Alison platform. It is free course where you can learn few multimedia tools like Adobe Photoshop, Windows Movie Maker, Adobe Flash, Audacity, Director MX and Adobe After Effects. I'm already familiar with some of those tools and I'm interested to see what new tricks can I learn.
Alison also offers free individual courses on PhotoShop, Flash, After Effects and Adobe Connect.