System Landscape on XI or SRM ?

Hello to all,

Actually I have to configure the system landscape for several systems, but I do not know which are the best practices that I must follow to form it.

I have two servers one of the XI and other one of SRM 5.0, additional I have in another server of SSM 3.2.

Would I like to know which is the best recommendation, if I must install and configuring SLD in the XI or SRM?. And if someone can indicate me where it he can access information that recounts me to this topic.

I have never formed the SLD in Systems SAP, estimated to anybody who could orientate me.

Best Regards,

Desiree