Please see the Embedding Using Dreamweaver instructions.
where do I put the juicebox folder to make it happen?
Essentially, if you follow the standard embedding instruction here, then you should upload the contents of your gallery folder to the same directory as the HTML document containing your gallery's embedding code.
Alternatively, if you use the baseUrl method of embedding (documented here) then you can upload your entire gallery folder (not just the contents) to your web server. It does not matter where on your web server you upload your gallery folder to as long as you know where it is and that the two paths within your gallery's embedding code (the path to the 'juicebox.js' file and the baseUrl itself) are correct.
No. There is no Juicebox plugin for Dreamweaver. Just follow the embedding instructions (either the standard instructions or the baseUrl method) and your gallery should display fine.