Maybe this is more of a rant on my 'web pet peeves', but I do believe that for 80 percent of the web, 80 percent of the visitors will be happier on your site.
First off, like any other design rule, there are no rules. Depending upon your needs an how specific your audience is, all of the following may not apply.
Viewer first It isn't too difficult to figure out a web sites purpose. In general they are all one of a few things. But thay all provide information for an audience. From there it where it gets very different. But I like to keep that first purpose, the most important. Even when a site is intended to sell products, I tend to take the less pressure approach. I also tend to trust the viewer that their eyes can navigate my website and easly draw them to what they want. Not what I want them to see. There is a huge difference there. Imagine you are shopping in a mall. Not for anything specific, but just looking around. I know what I like and the things I am likely to buy are where I shop. But how annoying is the kiosk people. I purposly re-route my course to avoid these people. You know the cell phone people, who don't care if you are currently under contract with another provider, they still want to waste your time. Or the people selling hair or fingernail products. Oh yeah they'll waste my time too. If I do not take a different route to my destination, I don't dare make eye contact. That is the kiss of death. I would think the mall should not be happy with these high pressure sales people. I have often thought of talking to customer service except I have already wasted too much time. Honestly this makes the visit to the mall less appealing. A trip to a website can be the same. Designated areas of the page like the right hand column has been unofficially established as the area for advertising. Most people understand this and it doesn't interfere with the content. I do think it is a bad idea to place the advertisement smack dab in the middle of the content area. Right were you are trying to read, nevermind the sponserlinks that are right inline with the text. You know the ones that have a double underline and a little bubble when your pointer hovers. The web survives on ads, everyone knows that. But taking the viewers eyes away from their information is a mistake in my opinion. Don't let your site become the mall people avoid.
Audio Especially when people are at work, in an area where there isn't much privacy. I can be extremely annoying to have to scramble for the volume control when a page opens and be default blasts some nonsense vai an ad or even a flash file that is part of your site design. I know any time I visit a designers site that automatically plays music, I look for the mute or volume on my computer or if the designer of the site was thoughtful enough to create controls in their flash 'presentation.' In certain applications, and a very narrow and targeted audience this may be permissible. Overall I would suggest no sound load automatically.