there was a thread on here a few weeks ago but i can't find it. so here we go again.
I've made a bash script to start my wifi card called wlan.sh, can anybody please tell me where i have to put it so that it'll start on boot, there seems to be quite a few of rc.d directories and i'm not sure what i'm doing. I'm running fedora core 5.

cheers guys

If you want to take advantage of having per-runlevel initscripts, format it like a proper service script and put it in /etc/rc.d/init.d (see scripts there for examples) and use chkconfig to link it to runlevels. This for instance would allow you to run wpa_supplicant in wait+background mode before bringing up networking which you can't do by stuffing the script in /etc/rc.d/rc.local.

EDIT: since it's related to networking maybe check first if the commands you use could be run from say the start section of the networking script. Else / if unsure just post your script.

well on fedora you need to put the script on /etc/rc.local which make it work on every boot no matter which run level the machine run, or if you want it to run only in specific init you need to put it on the appropriate /etc/rc(init number).d directory and then you need to to run the command :
the script must contain two lines at the strart like here in the example :

the first line is the chkconfig option wich tell the boot in which order to start the script at boot in the current started init and in which order to stop him when u change init or rebooting your machine. it only have meaning if your script depends on other daemon. if it does then it should start after the daemon.
the second line is the description line which contain the description on your script.
if the script wont contain those 2 lines the script wont run on boot.

See this old thread for reference.
It is for suse, but then, it is for reference.