I would recommend listenning to this series of podcasts from AstronomyCast:
Where is the centre of the universe:
http://www.astronomycast.com/astrono...-the-universe/
What is the shape of the universe:
http://www.astronomycast.com/astrono...-the-universe/
How big is the universe:
http://www.astronomycast.com/astrono...-the-universe/
... and... a question show:
Questions on the shape, size and centre of the universe:
http://www.astronomycast.com/astrono...-the-universe/
Roger.