Are you talking about putting them on an arbitrary website or do you use .mac?
If it's the former, I don't have that version of iPhoto on the Mac I'm using at the moment, but from what I remember you use an Export menu choice and pick the "web page" tab.
It creates a set of files (best to put them in a new empty folder) and you can then put all of those files on your website the same way you put other files on your website, usually with an FTP client.