I think videos will be more helpful :
https://www.youtube.com/watch?v=rOggrg-svPs
https://www.youtube.com/watch?v=eQo_k9WiLms
http://tv.adobe.com/watch/muse-feature-tour/muse-design-for-flexible-browser-width/
Additionally, you can try to use the menu from muse library :
http://muse.adobe.com/Default.aspx?CCID=32494&FID=162755&ExcludeBoolFalse=True&PageID=1524 0812
Thanks,
Sanjit