I don't see any concern related to Ram
If you opt to update the BIOS, be sure to disable ALL your Virus/Antispyware protection software beforehand
I'm not sure what Dell is selling their RAM for, but price it out
Here is a comparison
http://www.crucial.com/store/listparts.aspx?model=Inspiron%206000&Cat=RAMYou can also check out Newegg, TigerDirect, etc...
When it comes time to installing the Ram, if you haven't done it before on a Laptop
You may want to download the manual from Dell, it should have step by step directions
I usually unplug the power from the laptop, remove Battery, discharge power by holding down power button for at
minimum 10 seconds
Remove cover to Ram, typically on bottom of laptop
Remove Ram modules, normally spread tangs that hold Ram, lift Ram to about 30 degree angle
and pull out
But double check the manual