Hi,
What ADSL provider are you plan on using? Most provide wireless along with the modem. Some provide a separate wireless AP while others provide one integrated with the ADSL modem.
If you have a provider that supplies only the modem then you will need a wireless AP or wireless router. I would select the latter if you want to hardware additional equipment, most provide 4 ports.
You will need a network interface card (NIC) for your desktop if it doen't have the lan interface integrated to the motherboard. If needed, get a good PCI 10/100. Unless you are wanting to get into the gig lan standard.
For your laptop, if it doesn't have integrated wireless you will need a cardbus/pcmcia wireless interface. You should match the cardbus/pcmcia wireless with the wireless AP or Wireless router. That would be
802.11a,b,g. I would stay away from some of the super stuff at this time. Note that the chosen wireless standard will dictate your access (802.11a,b,g).Prices for the 802.11b equipment is low at this time. You could purchase a
802.11g wlan card for the laptop and still access your 802.11b wlan.I have not assumed any operating system. If you are Windows based then most equipment will have the needed drivers. If Linux you will need to check the card base id to see if the equipment is compatible and that the drivers are provided. You could use NDIS wrapper for linux based equipment but some of the chipsets used can cause some problems with older equipment.
HTH!