Keep it simple and avoid overwhelming people.
You might have noticed that over the past few years the main navigation menus on websites are getting smaller. There’s a reason for this and it isn’t because websites are getting smaller too. On the contrary – it’s because when you have too many choices your brain gets overloaded.
Hick’s Law is named after British psychologist William Hick whose work in the 1950s showed that the more choices people are offered the longer it takes for them to make a decision. If you offer too many choices people are more likely not to choose any of them.
Most people understand the idea of ‘chunking’ website information into logical groupings – like having a top-level About page with subpages for History, Team, Values – but it’s also important to not have too many top-level pages. Traditional wisdom – based on cognitive load theory’s ideas about the size of people’s working memory – is that your menu should have seven items at most. I’d suggest less if you can get away with it.
The smart approach is to feature prominently the main things people are looking for when they visit your site (or the things you want them to find) and put those in your primary menu. Instead of trying to have every bit of content on your site linked from a main menu show other, less important links elsewhere – at the bottom of the page or deeper into your site.
You’ll notice lots of sites don’t really even have a traditional menu anymore…
Of course every case is different and not everyone has just one thing they want people to do when they visit their website. The most important takeaway from all of this is that you should let go of the idea that you need every single page on your site in your main menu.