Boosting Network Range

Ok, I need help, I live in a 2 storey house, the cable comes in downstairs and I have the modem and router near to floor on the ground floor. My conection speed is pretty godd on everything when you are downstairs. However upstairs is a different story, my main laptop and PS3 are dreadfully slow. I have a Netgear WNR2000 V2 router connected. I also own a D-Link DIR615 D4, currently in a box!
What I would like to do is use one of the routers as a wireless repeater upstairs to boost my connection around the house, I've tried so many times and I just cannot work it out - I'd like to think I have some networking knowledge - but at the moment it all seems useless.
Can somebody give me detailed step by step (idiots guide) instructions on how I can do this, because basically - it's doing my head in!!!

You're situation is very common; and easily solved. I will warn you that if you have no networking experience it will be a challenge for you. I would suggest purchasing an Apple Airport Extreme and an Airport Express. You can setup the Extreme to broadcast your "main" wireless signal throughout the house. Then setup the Airport Express to "repeat" (it will say this in the installation setup) an existing wireless network. Walk through the setup and it the Express will now be repeating your "main" wireless network. Plug the Express in where the signal starts to get weak. This will be the easiest, but most expensive route.