My own rules for web site design :
Does it load quickly enough? If it doesn't, it won't get looked at.
Is what appears necessary, attractive and useful?
Is it too cluttered? Remember the K.I.S.S. principle!
Test the site with every browser you can get your hands on. Click on every link. Refresh every page.
Is the site easy to navigate around?
BTW, if you MUST use Java (and I generally recommend against it), test your pages again both Netscape 4 and IE 4 & 5. Far too many sites support only one or the other.
Personally I prefer to keep the intelligence at the server end and use CGI scripts. From the URLs it's obvious that this is how PPRuNe mostly works. PPRuNe does have some simple Javascript, but unlike most sites, the Javascript here has obviously been tested and works!