SEO (Search Engine Optimisation)
seositecheckup.com is definitely the best resource that I’ve come across so far for completely breaking down every aspect of a website’s SEO. I have greatly expanded my knowledge of SEO by testing websites with this resource and learning how to improve every aspect of the web development process.
I would also recommend that anyone who is interested in getting started with SEO should read Google’s Search Engine Optimisation Starter Guide.
Website Speed
tools.pingdom.com is a fantastic resource for testing a website’s speed and gives lots of helpful tips to improve areas in need of a fix-up.
Google PageSpeed Insights is another resource for testing not only the website’s speed but also how the website’s content is prioritised, the size of tap targets and font legibility.
Stock Images, icons, illustrations
unsplash.com is updated every ten days with new free, high-res stock images. The quality is excellent and they have an extensive library of photos touching on various themes.
icons8.com great source of illustartions, icons and images
thenounproject.com has the best collection of icons across the web!!!
Fonts
FontAwesome would definitely be my go-to icons for any website project. The font is available to download and install on your computer for use in Photoshop and there is also a web font available for use online. They are constantly updating the icon library.
fontshare.com obbers a ton of free fonts
Dashicons are very useful within the WordPress administrative screen when creating Custom Post Types.
Colours
brandcolors.net is great for ensuring you have the exact HEX value for Facebook, Twitter etc.
Adobe Kuler is a wonderful website for creating colour schemes.
flatuicolorpicker.com gives the HEX and RGB values for all of the colours within the flat colour scheme.
colors.muz.li Color Palette Generator
CSS
Less is my go-to CSS pre-processor at the moment. I find that it speeds up every project and keeps my files tidy.
HTML Newsletters
This tutorial is great for getting started with responsive HTML email newsletters. And this tutorial goes through creating a basic HTML email template from scratch.