Need to temporarily keep visitors from seeing store

How can I keep the MarketPress plugin active on the site so I can continue to work on adding products, but in the mean time do the following:
1) either put an Under Construction sign on the Products Page or make it so the products page is not visible to visitors (yet I can still get to it to work on populating it)

2) temporarily disable the Products and Shopping cart sub-menus

3) Permanently disable the Order Status page from the sub-menu and from the store page ... no items submitted to shopping cart will be shipped... they'll be ready at the eye doctor's office, so no need to track the order.

Thanks for your help.