Make sure memory is compatible with your motherboard check at crucial.com
Switch off and unplug
wear an antistatic wrist band
insert correctway round
check fully inserted in slot (needs firm push but don't force) end clips should locate easily if fully inserted.
when you reboot should count up to 1G without changing anything in BIOS.
If refuses to boot and beeps at you then not inserted correctly or faulty memory stick.
Best of Luck (you shouldn't really need it)