How to install n configure asterisk

hello friends,
Need ur help n support in configuring asterisk. plz forgive me as i am asking very basic questions as i am a newbie. plz guide me from where to start asterisk . i am giving details of my machine hardware.

O.S - Ubuntu 8.04 Lts
Ram - 1 G.B
Processor - Core 2 Duo
NIC - 2 NIC (Ethernet Card)

plz tell me what extra hardware ill be needing like any POE Switch, Ethernet etc.

any help support will be highly appreciated.