Providing that the links in your breadcrumbs are appropriately styled (i.e. they look and behave like links and look like the other links in your site) and have appropriately meaningful anchor textappropriately meaningful anchor text, then you shouldn't need to include the "You are here".
Other conventions are that the separators are either right angle brackets > or slashes / and the representation of the current page in the breadcrumbs shouldn't be a link.
ui-patterns.com suggests "you should not use on the topmost level of the hierarchy (typically the welcome page)", but does point out that breadcrumbs should always be used in conjunction with other types of navigation, never as the primary nav.
Some may argue that the breadcrumb pattern isn't universal enough, and we should design for worst case scenario users, but if you follow the above advice, all you're really presenting is a set of links of increasing/decreasing specificity.