You can use ssh to setup VNC on Raspberry Pi. VNC is a graphical desktop sharing system, like "Remote Desktop" - exactly what you need.
Step 1 - Power it up
By default RPi Distributions come with enabled dhcp and installed ssh server. So all you need to do is plugin your RPi into the network and check what IP address had it received (from your router active DHCP clients for example or by using nmap)
Step 2 - Connect to it with ssh
If you are using Windows download a tool called PuTTy. It's a tool for remote console management.
If you are using Linux issue the ssh ip_address_of_pi
command.
Next you will need to enter the login credentials for your Pi
Step 3 - Install vnc
Check what package manager is using your RPi Linux distribution. For Debian the default one is called 'apt-get'. Other package managers are 'aptitude', 'synaptic' and etc.
Run this to install vnc4server
sudo apt-get install vnc4server
That the most important. Follow some tutorial on the web for configuring vnc. There is an easy to use vnc client for windows and linux.
Good Luck!