If both computers are connected to your router for internet access, then they are already "networked" for "File & Printer sharing".
There is a Networking wizard in Control Panel, although some of its options are (IMHO) confusing. All you actually need to do is to right click those folders you want to have available over the network and select the "Sharing & Security" option. Similarly, set any Printer(s) you want to have available as Shared. Printer sharing click here
If you are running Firewall software such as Zone Alarm, this will need to be configured to allow access to the networked computers, which may involve adding their IP addresses in a "trusted" section.