Yeah you can post a Milestone without announcing it to all your Fans. There’s a box you can tick when creating the Milestone that will stop it from publishing it to News Feeds. It’s helpful for if you want to upload several Milestones all at once (like if you didn’t do much to your page when it first changed to Timeline, but now want to start creating your history).

For another example of a great looking Milestone history, check out the New York Times’ Facebook page. Someone told me about it today in work recently, it’s very good.