1. Become an Excel expert
Chandoo is one of many gracious Excel experts who wants to share their knowledge with the world. Excel excellence is one of those skills that will improve your chances of getting a good job instantly, and it will continue to prove invaluable over the course of your career. What are you waiting for?
2. Learn how to code
http://www.codecademy.com OR https://www.edx.org/course/harvardx/harvardx-cs50x-introduction-computer-1022
There are a lot of places that offer free or cheap online coding tutorials, but I recommend Code Academy for their breadth and innovative program. If you want to try a more traditional route, Harvard offers its excellent Introduction to Computer Science course online for free.
3. Make a wonderful website
http://iwanttolearnruby.com OR http://railsforzombies.org OR http://ruby.learncodethehardway.org
You could use a pre-existing template or blogging service, or you could learn Ruby on Rails and probably change your life forever. Here's an extremely helpful long list of free Ruby learning tools that includes everything from Rails for Zombies to Learn Ruby The Hard Way. Go! Ruby! Some basic programming experience, like one of the courses above, might be helpful.
4. Make a mobile game
If you're not interested in coding anything other than fun game apps, you could try this course from the University of Reading. It promises to teach you how to build a game in Java, even if you don't have programming experience!
5. Start reading faster
Spreeder is a free online program that will improve your reading skill and comprehension no matter how old you are. With enough practice, you could learn to double, triple, or even quadruple the speed at which you read passages currently, which is basically like adding years to your life.
6. Learn a language!
With Duolingo, you can learn Spanish, French, Portuguese, Italian, or English (from any of the above or more). There's a mobile app and a website, and the extensive courses are completely free.
7. Pickle your own vegetables
Tired of your farmer's market haul going bad before you use it all? Or do you just love tangy pickled veggies? You too can pickle like a pro thanks to SkillShare and Travis Grillo.
8. Improve your public speaking
You can take the University of Washington's Intro to Public Speaking for free online. Once you learn a few tricks of the trade, you'll be able to go into situations like being asked to present at a company meeting or giving a presentation in class without nearly as much fear and loathing.
9. Learn some statistics
UC Berkeley put a stats intro class on iTunes. Once you know how to understand the numbers yourself, you'll never read a biased "news" article the same way again — 100% of authors of this post agree!
Knowing the basics of psych will bring context to your understanding of yourself, the dynamics of your family and friendships, what's really going on with your coworkers, and the woes and wonders of society in general. Yale University has its Intro to Psychology lectures online for free.
11. Make your own music.
Step 1: http://justinguitar.com
Step 2: https://www.berkleemusic.com/welcome/free-voice-lesson
Step 3: https://www.coursera.org/course/songwriting
Step 4: http://lifehacker.com/the-basics-of-music-production-the-complete-guide-514079132
Step one: Learn how to play guitar: Justin Guitar is a fine and free place to start learning chords and the basic skills you'll need to be able to play guitar — from there, it's up to you, but once you know the basics, just looking up tabs for your favorite songs and learning them on your own is how many young guitar players get their start (plus it's an excellent party trick).
Step two: A delightful free voice lesson from Berklee College Of Music.
Step three: Have you always thought you had an inner TSwift? Berklee College of Music offers an Introduction to Songwriting course completely for free online. The course is six weeks long, and by the end of the lesson you'll have at least one completed song.
Step four: Lifehacker's basics of music production will help you put it all together once you have the skills down! You'll be recording your own music, ready to share with your valentine or the entire world, in no time!
12. Learn to negotiate.
Let Stanford's Stan Christensen explain how to negotiate in business and your personal life, managing relationships for your personal gain and not letting yourself be steamrolled. There are a lot of football metaphors and it's great.
13. Stop hating math.
If you struggled with math throughout school and now have trouble applying it in real-world situations when it crops up, try Saylor.org's Real World Math course. It will reteach you basic math skills as they apply IRL. Very helpful!
14. Start drawing!
All kids draw — so why do we become so afraid of it as adults? Everyone should feel comfortable with a sketchbook and pencil, and sketching is a wonderful way to express your creativity. DrawSpace is a great place to start. (I also highly recommend the book Drawing on the Right Side of the Brain if you can drop a few dollars for a used copy.)
15. Make your own animated GIF.
16. Appreciate jazz.
Have you never really "gotten" jazz? If you want to be able to participate in conversations at fancy parties and/or just add some context to your appreciation of all music, try this free online course from UT Austin.
18. Get better at using Photoshop.
19. Take decent pictures.
http://lifehacker.com/5815742/basics-of-photography-the-complete-guide OR http://www.shortcourses.com/display/
Lifehacker's basics of photography might be a good place to start. Learn how your camera works, the basic of composition, and editing images in post-production. If you finish that and you're not sure what to do next, here's a short course on displaying and sharing your digital photographs.
20. Learn to knit.
Instructables has a great course by a woman who is herself an online-taught knitter. You'll be making baby hats and cute scarves before this winter's over!
21. Learn how to invest stocks
22. Clean your house in a short amount of time.
Unf$#k Your Habitat has a great emergency cleaning guide for when your mother-in-law springs a surprise visit on you. While you're over there, the entire blog is good for getting organized and clean in the long term, not just in "emergencies." You'll be happier for it.
23. Start practicing yoga.
http://www.yogaglo.com OR http://yogameditationhome.com OR http://www.yogatailor.com
Most cities have free community classes (try just searching Google or inquiring at your local yoga studio), or if you're more comfortable trying yoga at home, YogaGlo has a great 15-day trial and Yome is a compendium of 100% free yoga videos. If you're already familiar with basic yoga positions but you need an easy way to practice at home, I recommend YogaTailor's free trial as well.
24. Tie your shoelaces more efficiently.
It's simple and just imagine the minutes of your life you'll save!