I would suggest you need something similar to what I have just bought click here
If I said it was simple to set up I would be lying but then again it was the first time I had ever done any kind of networking. Now it is up and running it works a treat and I have currently got 128 bit WEP encryption working but will probably have a dabble with WPA at some point. As you have a requirement for 3 connections you would need to buy an extra USB dongle or PCMCIA connection depending on your laptop. Hope this helps but others may be able to recommend other ADSL routers that work as well but are easier to set up.