Need help creating/building my server! :)

How do I properly port forward with a D-Link DIR-615 router because I have made a port forward with the following settings :
I.P Address: 192.168.0.102
Public port: 25565
Private port: 25565
Protocol: both TCP and UDP
Schedule: Always
Filter: Allow all

But when I try to start the server in the "server console" it always says:

[INFO] Starting minecraft server version 1.2.5
[INFO] Loading properties
[INFO] Starting Minecraft server on 192.168.0.102:25565
[WARNING] **** FAILED TO BIND TO PORT!
[WARNING] The exception was: java.net.BindException: Cannot assign requested address: JVM_Bind
[WARNING] Perhaps a server is already running on that port?

What am I doing wrong? Please be descriptive because I am pretty lost at this point.

Also, once I get the server running, I want to add some basic plug-ins but I don't know how, what to get, etc. So I will need help with that AND I would like a couple (max of 4) to help me build my server up, I have a little area started but it still has a LONG way to go. Thanks for reading and/or helping!