Thanks to Jonathan (daMaestro), I got the Qemu bridge working. The howto I followed from watzmann.net does not work for me because of what I believe some missing details for me understand the setup and set it properly.
Creating a Bridge
Lets assume we want to create a bridge called br0, which will be bridged to eth0. The host will be using a static IP 192.168.0.20 on a /24 network, with a gateway 192.168.0.1.
Edit /etc/sysconfig/network-scripts/ifcfg-br0. Change it to be similar to this.
Then, edit /etc/sysconfig/network-scripts/ifcfg-eth0 to this.
(Replace $MACADDRESS with the MAC address of your network card.)
Afterward, restart the network `/sbin/service network restart`
From this point, you should be able to select the bridge when you are creating a new VM through virt-manager.
You will need to set br0 as a trusted interface through system-config-firewall before you'll be able to use the network.
Yay, now I feel much more comfortable on Qemu.