An author's website is usually the hub of their presence on the web.
Any website will always be a work-in-progress, constantly evolving and never finished. Once they are "good enough" they go live (and often they go live when they are still in need of a bit of work). This is quite reasonable: an author's career never stands still and what an author wants from their website will keep changing, with each change incrementally improving.
Different authors will have different aims and will want to stamp their individual personality on their own website. As with writing a book, there is no empirical measure of the "right" or the "wrong" way with a website. Designing a website is all about making choices—there are no wrong choices, but there are definitely some things an author can do which will not support the author's aims.
The area where author websites fall down is not the content, but the implementation. Many try to be too clever, or get obsessed by looks, or let their designers run wild. This note looks at what authors should do, and also considers some of the practices that should be avoided.