I just saw this in another forum but found it to be a very useful little list for getting information when requesting help troubleshooting.
ls (list directory contents)
cat (concatenate files and print on the standard output)
id (print real and effective user and group IDs)
uname -a (print system information)
lsb_release -a (print distribution-specific information)
ifconfig (configure a network interface)
route -n (show/manipulate the IP routing table)
cat /etc/resolv.conf (displays the DNS information)
cat /etc/network/interfaces (displays the network interface configuration)
cat /etc/hosts (static values for hostname lookups)
lspci (list all PCI devices)
lsusb (list USB devices)
dmesg (print or control the kernel ring buffer)
lsmod (show the status of modules in the Linux kernel)
ls -lisart /var/log (the location of the actual logfiles)
Cheers,
Tim