Well if you looked at the home page, it tells you pretty much everything you need to know to build one. I suggest having a hammer and a pair of pliers ready as the connectors can be hard to connect. Also zip ties are very useful in case you run out of connectors.
Guinea pigs are social animals who live in herds in the wild. They do much better if kept in at least pairs. And since you haven't gotten your pigs yet I'll remind you to adopt! There are tons of homeless guinea pigs out there who desperately need a good home.
www.petfinder.com is a good place to start. If you have any trouble, we're more than willing to help you find a pair.
Also as far as guinea pig care is concerned this thread is a collection of the best information on the web. Please read it before you get the pigs so that you know what to expect and how to care for them properly:
http://www.cavycages.com/forum/showthread.php?t=17032
If you have any questions feel free to ask! Good luck and have fun!