Mac Newbie Basic Questions

Hi, I just got my first mac a couple days a go..Its a 17" MB Pro 4GB Ram 2.8 processor. My Questions are:

1. On the website it gave the option to have 8GB ram, does this come on 2 chips or 1 Chip? Just in case i wanted to upgrade later.

2. How do i know what is exactly in my mac? Like the hardware. In windows i would just right click on My Computer and choose properties and it would list whatever i had, like my memory, vcard etc etc...

Thanx in advance

Hold down option key and click on Apple menu - top left - and select Profiler and there is a memory selection in the profiler

Go to the apple in the top left>click about this mac>click more info. That should tell you everything you want to know.