Setting a page as my home page

I’m sorry if this is really basic but I have been clicking around for an hour and have not resolved this simple question.

I have a blog WordPress 2.6.3 on my website and I want a particular post (or it could be a page) to show up as the home page, i.e. the one that shows up when people click the base blog URL. It seems that when you write or edit a post, there should be a checkbox “Set as home page” but not so.

I have read in a couple of places that you can set a particular page as the home page in the “Settings/Reading” area. Not so in mine! The options in Settings/Reading are:

Reading Settings
– Blog pages show at most
– Syndication feeds show the most recent
– For each article in a feed, show
– Encoding for pages and feeds

Nothing about setting the home page.

Can someone please shed some light with specific instructions on how to set a specific post on my blog to show up as the home page?

Thanks!