Simple rather than flashy:
The use of multimedia can help you provide all kinds of features making your web pages lifelike and interesting. However, it is advisable to avoid its use if you really want your prospective visitors to gain quick access to your website and obtain the relevant information. It is a good idea to limit flash navigation, which can confuse users if over used. Always make access to your Home page direct from any page.
Focus on speed:
Files with graphic formats should never give users long download times or they will be driven away. Remember search engines find it hard to decipher text embedded in graphics and these features take longer to download. Avoid such things as far as possible. Have a look here for more technical tips on website loading and page design.