You just need a amplifier and make a sound connection with it (audio out) from your laptop and (audio in) in your amplifier attach your external speakers with your amplifier.
I have my laptop hooked up to a flat screen monitor with Speaker's, what do I need to do to get sound out of speakers on monitor.
All you need is a pair of computer speakers (they are magnetically shielded). The cost of speakers varies on sound quality and output. Plug them in your laptop's built in sound card speaker port.