Here are a couple options. With lighting you will have to replace the existing switches, and be careful to address 3 way systems where 2 switches control one lighting load.
A couple ways that are easy. . .
Insteon has a starter kit with a web portal for remote access. It is like PLC so no repeaters are necessary as they use powerline for communictions.
Lutron Radio RA2 can use a control interface to the main repeater that wirelessly connects to your switches. You have to plan for repeaters in these system based on the distance between switches.
There are many options, but these should get you started.