Ingrid - Get a laptop with good warranty as they are pricey to repair. As to their shelf life, they vary drastically. I have seen a guy using a 9 years old laptop (Apple PowerBook 5300) typing up his paper in the library and still running strong. On the other hand, my 3 years old Toshiba Protege 7200 always freezes whenever the computer gets a little too warm. I have heard cases where the LCD display fails within the first year of use. So it really depends on your luck. Get one from a reputable company and if something bad does go wrong, you have the warranty to back you up. It also depends on how gentle you are with your laptop. For example, if you accidentally drop your laptop or bang it against something, that can't be good to the laptop.
Massagegirl - The video card has a VGA port (the blue interface in the picture) at the back where the monitor cable attaches to it. Of course, your card may have a different colour VGA port. You lift up the end where the VGA port is located first. Once that is loose, lift the other corner and card is out. To put the card back in, insert the opposite end of the video card (not the VGA port side) into the slot first, then push the other end (VGA port side) into the slot. Once the video card is seated properly, it should not wiggle around. This shouldn't be too difficult for you.
I apologize if my instructions are unclear. It is getting late and I am tired. Good night.