DLL is not supporting in windows 7 phone application using visual studio 2010-Collection of common programming errors

If I add any dll (like sqllite3.dll, sqlliteclient.dll) I get the below message:

Reference cannot be added to l because it was not built using the Windows Phone runtime. Windows Phone projects will work only with Windows Phone assemblies.

I could really do with a clean slate to start with that. Kindly provide simple database connection using database with reference dll.