xmarks is very simple,
the beauty of xmarks is that if you want to use your favorites from a different location,town ,country etc then you just need to visit the xmarks site and log in to get your bookmarks.
there is not much to it,
install it for your browser /s and create an account.
you can also sync your bookmarks across different browsers, ie, if you install xmarks for internet explorer and firefox and chrome, whenever you use either browser you have the bookmarks list identical.
backing up your bookmarks without a third party is fine ,as long as you dont want to access them from elsewhere or are happy to carry a back up around should you do!