Okay, in Windows, the routing table entries are setup like this:
Network Destination (the destination network number/subnet i.e. 192.168.0.0 (specifies what network this route is to forward to))
Netmask (the subnet mask of the destination network i.e. 255.255.255.0 (specified so the TCP/IP stack knows what the broadcast addresses are and the addresses of multiple subnets))
Gateway (the next "hop" to the destination network i.e. 192.168.1.1 (specifies the first router to forward packets that apply to this route to)
Interface (the interface on the computer/router that the packet will travel out of i.e. 192.168.2.1)
Metric (known as "Administrative Distance" in this case- specifies the trustworthiness of a connection; usually determined by delay, bandwidth, load, etc.)
So the format of an IP routing table entry is like this:
Desintation Network Subnet Mask Next Hop Outgoing Interface Metric/Administrative Distance
A.A.A.A 255.B.B.B C.C.C.C D.D.D.D E
So, basically... The routing system uses routing tables to determine the routes packets will travel along FROM itself when it receives packets from itself or other hosts. All of these routes can be manually entered - Static, dynamically aquired from other routers - Dynamic. The format for most routers for a static route is basically the same. On a Cisco router, you add a static route like this:
Router(config)# ip host A.A.A.A 255.B.B.B C.C.C.C Name of outgoing interface i.e. Ethernet 0 E
I hope that's a good enough explaination for ya