Elsalam 3lekm,
ana Samir, I hope to be usefull, so I will talk about linux redhat enterprise 5 installation, sorry I will talk in english cuz it will be very difficult to guide you in arabic through this..
In general we have two kind of installation Stanalone and Network Installation..
so we use the first one when we are working in small environment of servers then it won't be difficult to use the OS DVD or CD's in each server.
the other kind "Network Installation" will be used in the heavy environment which we have too many servers and some times we need to install OS simultaneously in more than one server. I will assume that you know how to install linux using the OS DVD 'which is only to insert the DVD and keep pressing next until you get the linux desktop', if it's not clear pls tell me then we will do it together, otherwise I will move directly to the network installation.