big legacy database with complex many to many relationships

I have to integrate to a large read only legacy mssql database .

 

The many-to-many tables have a lot of additional fields like start/end dates of the relationship and their own naming conventions

 

Can anyone point me to some links that treat this topic in depth.  I’ve looked at the django book and that’s a starting point,

 

Can anyone point me to some good “how to” links on this that provide some details and some pitfalls to watch for.

 

Thanks

 

Fred.