Flash or Flash?
How flash do you want to make your site? You can fill your site with fancy animations, java applets, loads of big pictures and images, a nice Flash(tm) splash screen, or you could bear in mind that most people still access the internet via modem!
There's nothing wrong with animated graphics. Well nothing very wrong, if they're used carefully and sparsely.
You should aim to keep your first page as small and quick to load as possibly. A commonly mentioned figure is 80k. But be daring. Keep it under 60k. If you're tempted to go mad and spend hours playing with graphics or flash, always include the option to escape! A recent computer design magazine through scorn on a site for being too content led! Until 56k modems are extinct, there is no excuse for overloading your site with graphics, animations, video or sound.
A final word on flashy stuff. Don't ever ever ever put music on any opening page. Its very frowned upon in most net circles.