Below some sites that I thought were useful for making my website:
Github & Shiny
This website was ‘forked’ from https://github.com/daattali/beautiful-jekyll.
For some cool features (particularly the shiny-apps-page), I have had a close look at Dean Attali’s [website]((http://deanattali.com/) and Github.
I also learned more from RStudio’s shiny examples.
HTML
This is useful for testing features of HTML: http://jsfiddle.net/kyagn39h/12/, https://www.w3schools.com/, http://matthewjamestaylor.com/blog/adding-css-to-html-with-link-embed-inline-and-import, https://medium.com/@jamesfuthey/simulating-the-creation-of-website-thumbnail-screenshots-using-iframes-7145269891db and http://matthewjamestaylor.com/blog/perfect-3-column.htm.