My advice is: visualize as much as possible. Posters live from being easy to digest. If people see clutters of headings, paragraphs and some images randomly thrown in they usually get lost and bored. I once was told that a person in a crowd is not willing to spend more than five minutes looking at the poster, the very first seconds decide if a closer looks is worthwhile (pay attention to large objects and the title).
Help people by navigating them through a poster (arrows, clear spacings, headings with numbers, ...). It seems trivial but most people are used to read from top left to bottom right, so don't interfere with that.
Don't forget about choosing an appealing colour theme (if desired) and assigning colours to messages and objects (e.g. all subheadings have same colours). Think carefully about background pictures as they may distract.
On your website you have a lot of text; get rid of all information that don't contribute to your main message. Focus on this very message. You don't have much space to waste. In case you are presenting the poster have some handouts ready (preferably repeating the theme and layout of your poster) that contain the website address - most people will not write it down or remember for themselves. Also put it on your poster.