embedding a unity3d player inside rapidweaver

How do I embed a player inside the blog of rapidweaver?

You just need to add a page of type HTML and then paste the appropriate code (from the default .html the web player build produces). Then in the page setup stuff in Rapid Weaver add the webplayer file. You will need to verify your paths are correct because of the way that rapid weaver adds a folder per page created and a files subfolder that would hold the actual webplayer.