i would recommend CMS Made simple or CMSimple..
CMSms is a bit more advanced then CMSimple, but it is super easy to set up. CMSimple has that bonus, that it works without a db. The content and man navigation is based on 1 .html file (navigation made out of the <h1> etc tags)
CMSms is a bit more advanced, but as already stated, super easy to set up.
/charnley
ps, i am not allowed to post urls (since i am new here), but i guess you can google it..