So after finishing school, I got an increased urge to learn stuff!
Here's my list of nice and free online learning resources. (Mostly but not exclusively videoseries!)
If you know other good/fun sites to add to the list, please share with me!

VARIOUS SUBJECTS:
Khan Academy  Huge videolibrary, mostly Salman Khans soothing voice explaining things while drawing/writing on a Photoshop blackboard. You can also do exercises, earn badges and so on.
Brady Harans videoseries  He interviews scientists and experts in series like "Periodic Table of Videos" and "Numberphile"! Also on YouTube.
TED-Ed  High production value videolectures!
Wikipedia  Of course!
Wolfram|Alpha  Sort of a search engine that uses its immense database of human knowledge to calculate stuff!
MITK12  Videos explaining various subjects made by students at MIT.
CGPGrey  Explains stuff
1Veritasium  Explains stuff for people through demonstration and interview
CrashCourse  Partially animated crashcourses in biology and history!
SciShow  Science news and discussion
Smarter Every Day  Stuff
Scale of the Universe  A cool interactive Flash infographic thing

BIOGRAPHIES/HISTORY:
CloudBiography  Bite sized biography videos
SmartHistory Teaching Art History in a casual discussion sort of way

MATH:
ViHart  Interesting math stuff (She got Nickelodeon to change Spongebobs pineapple because the pattern was mathematically incorrect)

PHYSICS:
MinutePhysics  Short animated physics videos!

CRYPTOGRAHY:
ArtOfTheProblem  The history and theory of cryptography!

PROGRAMMING:
Codecademy  It's interactive!

I didn't include documentaries (Okay here's a couple: Attenboroughs "Life" series and Sagans "Cosmos" series) or books (Okay here's one: Bill Brysons "A Short History of Nearly Everything")