These links should rock your world:
http://www.gamedev.net/reference/articles/article747.asp
http://www.gamedev.net/reference/articles/article748.asp
and there's a ton of more links here:
http://www.gamedev.net/reference/list.asp?categoryid=44#198
If you need a book, try Isometric Game Programming with DirectX 7.0, by Ernest Pazera
ISBN: 0-7615-3089-4
http://www.gamedev.net/reference/articles/article747.asp
http://www.gamedev.net/reference/articles/article748.asp
and there's a ton of more links here:
http://www.gamedev.net/reference/list.asp?categoryid=44#198
If you need a book, try Isometric Game Programming with DirectX 7.0, by Ernest Pazera
ISBN: 0-7615-3089-4