Last time I tried this with Peanut Linux, I think I just plugged in the card, it started working by itself!
Tell us which version of Peanut, and what kind of NIC card are using.
Are you sure it isn't working? Do an "lsmod" after you plug the card in and see if the driver for it got loaded. If I remember, Peanut defaults to a DHCP config, but you can configure the IP yourself, I just don't remember how.
PS: For those who don't know, Peanut is just a nicely stripped down mini-Slackware based distro.