TREX installation/configuration

Hi,

I have 3 portal servers.

I wish to install TREX and make the configurations.

Can you please give me a good document/link for doing so.

Also let me know if any optimizations would be required.

I read that TREX should be installed on a new seperate server.

What are the Configuration requirements in terms of RAM, space etc for the TREX server?

Can I have TREX on the TREX server pointing to all my 3 portals?

Thanks.