How can I close my blog to the public?

Hi all,

I’m all done setting up my WP as a CMS locally and in a couple of weeks, it’s going live.

What I would like, is to have the site closed hile I work and open it to the public once it’s all setup. If I can do this, I could start moving it now and have it closed until I have enough good articles for opening day so I don’t find surprises that day.

Thanks in advance!