Original intent

When it comes to the Constitution of the U.S., most American Christians are quite adamant about how it is interpreted.  Most would insist that we should follow the original intent of its creators, and it is no different for judicial law, which seeks to protect the law from distorted variations of that intent.  (This article is a good example... http://www.worldnetdaily.com/news/article.asp?ARTICLE_ID=29647)

Many Christians would argue that the original meaning of the Bible is preserved throughout time and through the process of interpretation and cultural change... the Word is preserved.  It may be true that truth is preserved, but how easy is it to find that truth?  Many assume the Bible can be taken at face value.  I believe that, for much of the Word, this is true.  But it is also dangerous to assume that we understand or that the truth is there, plain to see.  Every text, even the Bible, requires that every reader interpret its meaning through their own eyes and in the context of their own experiences.  

So, what model of approaching Scripture will work?  If the truth is not always apparent, how do we know original intent?  And is the key to all things in that intended meaning?