Part of the beauty of Wi-Fi is that you have a variety of devices all over the house and they are all connected to the same network. Getting those devices to talk to each other, however, is not so simple—unless you know about the right software to use.
The simplest option for PCs is just to use the Windows HomeGroup feature first introduced in Windows 7. This will let you share printers, music, videos and documents. For mobile devices, tools like AirDroid, Pushbullet, and Doublou WiFi File Explorer can help move data to a PC. Finally, if you want to keep a folder or set of folders in sync, then your best option is BitTorrent Sync.
Some of these tools don’t necessarily require you to be on the same network, but things tend to go faster when they are.