Answer:
There is no official method. However users typically prefer first and foremost websites that function flawlessly- in all browsers, without any browser-specific 'glitches'.
Secondly, it should be easy to navigate and find the resources you are looking for. It should not appear 'cluttered' or 'spammy'. Avoiding advertisements and having a search option greatly improve this, as do having larger, clearly market buttons and avoiding excessive color 'splash' which can make things hard to miss or spot.
Thirdly is speed and performance. A website should load and respond quickly so that even users on slower connections and computers will not have problems.
Fourthly is compatability. You should avoid extremely proprietary technology or computer-specific technology that will not work on all computers, or that require special downloads and installation.
Despite it's popularity, Flash is best avoided as a necessary component of site navigation, due to it's poor reliability, poor security, difficult navigation, and slow performance. Some computers cannot run flash, even with downloaded content.
And finally is availability. The site should be online as close as possible to 100% of the time, without interruptions or downtime. While short-term outages for maintainance are acceptible, longer than a few minutes can cause users to avoid your website, mistakenly beleiving it to be non-working.