There are many different design principle, for different interfaces, some principles would be used for all types of interfaces.
one principle would be "Don't make me think".
You don't want to be giving people too much information to think about, people like to be able to get on with things without having to consider everything. All the information should be given as uncomplex as possible, most people nowdays will not read through all the details anyway, so you can spend more time making the interface more usable and visuably pleasing instead of explaining everything. Its good to make things basic but with a good visual impact.
Another principle would be Navigation and orientation.
People need to be able to get around your interface without feeling lost or finding it hard to find things. It should allways be clear where abouts you are, with lables and information to make it obvious.
The menu has to be easy to use and not move about the place, wherever you are on the site it should be easy to get back to previous pages without going far or being confusing.
Another principle would be using Conventions.
The internet has been out for awhile now, and in that time peopel have become familiar to certain things which you should use in your own interface. It is much easier to use things which people recognise then come up with new ones, this is also making people not have to think like a previous principle. If you use symbols for things which are usually used for other things, this could confuse people and be irritating.
Another principle would be Analysing Audiences.
You need to know what the main audiences visiting your site would be, this way you can cater to the majority of the needs, creating more visitors because you're being specific. but then you also need to cater too all the visitors needs, the main audience is just to help focus site design and information to have the best outcome. Different audience classes can help you know what to include on the site, if you give information about different things, its good to know if you should have more information about one thing than another.
Another principle would be "Watching what people do".
There are different ways you can 'watch' where people go on sites which would help you in designing your own. you could use testing, to see how someone uses the site and how they get around; which would help you bcome a better web designer, because theres alot of things you wouldnt realise people do on the site unless you test it. Theres ways you can see where people click on sites, like heat maps, which give you more of an insite in where people go the most.
