To do this, first select the album you would like on the web. Next, click on the Add Web Gallery button. From here, you can choose your theme and other settings. Once you're finished, just click on the Export to .Mac button, and then it's all done for you.
But you don't need .Mac to publish. Instead, click on the Export Web Pages button next to the .Mac Publish button. What this will do is generate HTML documents with all the images. You can then use any server you like to host the album.

