Newb Question about Airport Express Hookup

The Airport Express has an optical/analog 3.5mm audio out jack, similar to a headphone jack on an iPod. you can't plug it directly into standalone speakers like you have. You either need to put the audio from the Express into an amplifier, and the amplifier drives your current speakers, or get a set of powered speakers (where they can take that low level of sound and amplify it themselves). There are a number of small, cheap amplifiers that could work, a well-regarded one is the Lepai LP-2020A+. It depends how much power you need, how big the space is, etc. If this is just for listening to music in your office, that setup would be fine, but if you're trying to watch movies in the living room, it will probably be woefully underpowered.