I have had up to six computers (4x laptop + 2x desktop) wirelessly connected to my wireless router at the same time - the router also has four RJ45 Ethernet ports into which I am able (don't bother) to hard-wire another four machines.
You need to equip your two machines with either/or Wireless capability / ethernet port - and buy a wireless router and a connection contract with an ISP - You will need an Ethernet cable of appropriate length if you want to hard-wire. Some of the required hardware will very probably already exist in your machines - Likely Wireless in the Laptop and Ethernet port in both desktop and laptop.
Peccavi, November 2009