You should be able to use Contains or Freetext as methods on a TEXT or NTEXT column, passing a string parameter, but there is no support for anything like FORMS OF; that's a bit too specific to SQL Server.
So:
var dubstepAlbums = db.Albums.FindAll(db.Albums.Description.Contains("dub-step"));
If that doesn't work, please report it as a bug at the project Site.