My new computer will be here soon and i wouldn't mind giving Leopard a go.

I've never used a mac before so this is totally new to me.

The hardware i purchased is..

Asus P5QL Pro Motherboard
Intel Dual Core E5200 (2.5GHz)
4GB TwinX pc6400 Memory
ATI HD 3450 PCI-E Graphics Card
M-Audio Audiophile Sound Card
250GB Seagate HDD S-ATA II
LG S-ATA DVD-r/w

Would anyone be kind enough to point me in the right direction? I'd like the latest version of OSX if possible. and how i can get it running correctly.

Much appreciated.