I'm not clear about what you want to do from your description.
For a wireless network card, there is a site (can't remember where) that lists the ones that work. My AirWay pcmcia card works fine with Mandrake 9.1, for example.
At that stage you have a Linux computer which is on a network and, presumably, a wireless router of some sort that it talks to.
Are you saying you then want to use this server as a web server and mail server? If so, you need to give details of what you want. However, there is a huge amount of information on the web about setting up a web server (e.g. with Apache) and a mailserver (e.g. with sendmail or other simpler packages) so it might be worth taking a look at those first.