I'm not sure how to check that, but I ran Yast online update and installed everything from that.
Start YaST, go to install/remove software, use the option "search" in the pull-down menu on the left. Type in "kernel" and look for "kernel-source". If it´s not checked, the sources are not installed. But you will run into problems if you do that, because you already updated your kernel with the online update. This means that the kernel on the CD/DVD from which you installed is older than the one you got via online update - so the sources will not be of the same version too. You can try to install the older kernel from the CD/DVD and then make an online update - then the sources should be updated, too.
It didn't work with the $ in front but here's the output of "lspci":
The $-sign is often used as a short version of the prompt (in your case "linux:~ #").
02:03.0 Network controller: Broadcom Corporation BCM4309 802.11a/b/g (rev 03)
That´s the exact name of the included wlan device. Did you try google? Greets, Dennis