Yes. Connect the headphones-out jack of the laptop to the Aux-in jack of your amp/receiver. You may need an adapter to go from the laptop's 1/8" headphones-out TRS connector to the RCA connectors on your amp/receiver (Radio Shack, Best Buy etc.), but that's basically it. See
this Wikipedia page for the connector types mentioned.
PS, since you can regulate the sound level of your headphones-out jack, you may want to take care not to overload your Aux input. Start with the headphones and amp volume low, and adjust until you have a good volume range from the laptop control without distortion.