you could manage with a switch, but may as well get a router (slightly different).
find out what sort internet you have (ADSL or cable, basically). then, does your modem have an output that looks like a larger telephone socket? you then plug an RJ-45 or "ethernet" cable into it, then into your router. the two laptops can then connected from the router.
you may find that your modem that was supplied by the ISP only gives usb output, and may find it hard to find a decent router accepting usb input. here, you'll need to buy a router with built-in modem.
if you want to go the extra hog, you can get a wireless router which does the same things as explained above, but also transmit your internet connection wirelessly. thus, you could access the internet from your laptops wirelessly (assuming your laptops have the required WiFi cards)