Question: I want other computers (they are in local network) go to Virtualbox Localhost. can you explain me what to do or at least give me article link.
in Virtualbox i have installed fedora19 and computers system is Windows 7.

Answer: 
Guest in bridged mode will use same IP subnet as the host, other computers can access it directly. If it is in NAT mode, you can use port forwarding so when other computers access to specific port of the host, the traffic will forward to another port of the guest.

[Here](https://www.virtualbox.org/manual/ch06.html#natforward) is the Virtualbox documentation, but I think the best way to learn it is just try a few settings to experiment it.
You probably need to change the network adapter settings to bridged mode. Right now, it's probably set to NAT'ed mode.