LINQ beginner, table joining query for document version - linq

Question

I have a Document table and a Version table. Both have identical information. Whenever a document is created it is inserted into the document table. Whenever that document is then edited a line is added to the Versions table.
It has a field dateApproved which will be null until it is approved. I am currently working on a MVC 4 Approval page and I have never touched linq before and it needs to be done in linq.
How can I join these two tables Document/Version and only show items where dateApproved is null?
from v in Versions
select v
from v in Document
select v
EDIT #1
A user adds a brand new document, this document is then added to the document table. At this point the document needs approval. The dateApproved field in the Documents table is null. Lets say this document gets approved, then the user makes a change and since this document already exists a line is added to the Versions table. Now this document exists in both tables the original document having a revision 0 with a dateApproved, and the Versions table have a revision 1 with a dateApproved as null.
What I need is the documents where the dateApproved is null weather this null is in the Documents table or the Versions table. After it is approved we leave the line in the Version table, and update the line in the Documents table with the approved version.
The key primary key is DocumentID.
EDIT #2
Thanks to Peter Kiss it is now displaying all the files that need to be approved. There is one more hiccup I am running into. It is returning 3 results which is correct. 2 files are brand new and 1 has been edited.
The 2 brand new files it displays the information correctly as from the documents table. The edited file it is displaying the information from the documents table but I need the info from the revisions table. Is it possible to make it return the version table information if the item exists in the version table and return the document table information if it does not exist in the version table (ie brand new).
Hope I explained that properly.

Answer 1

var documents =
ctx.Documents
.Where(x => x.dateApproved == null
|| x.Versions.Any
(y => y.dateApproved == null));
The documents variable will contain only those documents which are having unapproved versions. Then when you iterating through this collection the current document can reach it's Versions (all) through a navigation property called Versions. In that collection you can filter the unapproved versions.
All this only happens when the mapping is set up correctly (aka foreign keys) in your context.
After Edit #2
class DocumentToApprove
{
public string Name { get; set; }
/* other stuff */
public int version { get; set; }
}
var documents = ctx.Documents
.Where(x => x.dateApproved == null
|| x.Versions.Any(y => y.dateApproved == null));
var toApprove = from d in documents
let v = d.Versions.FirstOrDefault(y => y.Approved == null)
select new DocumentToApprove
{ Name = d.Name
,
/* other stuff */
Version = v == null ? 1 : v.VersionNumber
};

Answer 2

Select only records which are having dateApproved is null. and collect it in some kind of list listofVersions.
var listofVersions=(from v in Versions
where v.dateApproved==null
select v).ToList();
You can do the same for Document. Just substitute Version with Document.
Note: I just collect it with var to make it simple. You can create a list of Versions/Document if you wish.