We use a Netgear N900 wireless dual band gigabit router. Can plug in a USB hard drive, and all on the internal wireless network can access it. We can all access our older HP color laser printer also, so it acts as a print server.
We had a passport 500 GB harddrive plugged in, it looked like it was spinning the harddrive constantly, so we use a Lexar 32GB USB stick (biggest we had on hand) as the network hard drive instead now for file sharing between computers. Just put a 64 GB SD card in my smartphone, so we'll probably put a bigger USB stick online at some point for files. I see PNY brand 128GB sticks at BestBuy for $41, Lexar 64GB sticks for $19, $20.