Hi there, Joanna!
Embedding synths or panos from Photosynth on your site should be as easy as embedding a YouTube video on your site. Just copy the HTML embed code and paste it into your site's page.
When you paste it, there are three things you can edit to fit your needs:
1) Whether your page visitor must first click the synth once to begin it loading, rather than letting it load automatically along with the rest of the page: For your purposes where there will probably only be one synth or pano per page, I would recommend that you set the &delayLoad switch to 'false', rather than the default of 'true'.
2) Whether the synth or pano is playing its slideshow as soon as it loads or not: Similar to the previous switch, you would turn the &slideShowPlaying switch to 'true', rather than the default of 'false' in order to allow a synth to play through its photos or a pano to play through its highlights without your user manually clicking 'Play' or 'Next'.