What have you tried already? What guides did you use? What is the network setup of these boxes that you are trying to connect (eg, are either of them behind NAT)? What problems or specific errors have you encountered? What program are you using on Windows?
This is a good guide if you haven't already tried it:
Setting up VNC on Fedora 16.
One thing people often forget is to open the appropriate firewall ports. The guide talks about iptables, but in Fedora 19 it's actually firewalld that you need to interact with to make the changes permanent. I'm an iptables diehard, so not intimately familiar with firewalld, but I think this is what you want:
firewall-cmd --permanent --zone=public --add-service vnc-server