A few good (free) Websites

Unsplash

Unsplash has quite a wide variety of stock photos. They add 10 photos every 10 days, and you can opt to have them delivered to your email. Most of them can be used as cool website backgrounds or cool wallpapers. Either way, they're free

http://unsplash.com

Another good website with plenty of stock photos is http://www.allthefreestock.com/

Project Euler

Project Euler is one for all the programmers out there - beginners or advanced. Project Euler present you with a problem and you have to give a solution. SImples. Well, kinda. All of the problems require a lot of thought and you will need to do some research to produce an efficient solution to many of the more difficult problems. Either way, they're interesting problems. You can sign up as well to keep track of your progress, which is neat.

http://www.projecteuler.net

Codecademy

I've included this because, whilst it is very popular, it is still very useful especially if you want to start learning a new language. It offers free coding classes in 8 different programming languages including Python, PHP, jQuery, JavaScript, AngularJS, and Ruby, as well as markup languages HTML and CSS

https://www.codecademy.com/

Forekast

In a nutshell, It's a list of notable upcoming events posted by users. I like it.

https://forekast.com/

Google Fonts

Posted because it's really very useful. You can download fonts to use locally or you can utilize the font database and link fonts to your webpages for use online using @font-face. Quite a few of the fonts on here are pretty shit, so there's a cool list that gives the top 20 - http://www.awwwards.com/20-best-web-fonts-from-google-web-fonts-and-font-face.html

https://www.google.com/fonts

Khan Academy

Sort of a cross between Udemy and Codecademy, Khan Academy feaures micro-tutorials posted as YouTube videos on a broad range of subject such as math, art, computer programming, economics, physics, chemistry and history

https://www.khanacademy.org/

Material Palette

Really useful for web designers is Material Palette. You choose any two colours that you want and it generates a palette for you to use. If you like your selection, MaterialPallete tool allows you to download it and implement into your own material design

https://www.materialpalette.com/

Project Gutenburg

A resource which more people need to make use of. It's a digital library of free ebooks all in 3 formats - HTML, epub and mobi. If you have an ebook, you can drag and drop files across. Pretty much all the books it features are old, which is why they're all free. If you want to torrent books which aren't here, you can do that

https://www.gutenberg.org/

http://en.bookfi.org/ - A really useful site with fucking tonnes of ebooks. If you want/need it, it's probably here. Not just textbooks either.

Typeform

It's a neat site where you can make nice looking surveys and online forms really easily and really quickly

http://www.typeform.com

ZenPen

Type loads of stuff in your browser. Also if you close it down accidentally, you can open it back up and everything you wrote will still be there

http://www.zenpen.io