We are going camping over a long weekend and want to build an Eruv. Can you instruct us the simplest way to build a kosher Eruv in a small area?

There are too may variables to give simple instruction (terrain, tents, buildings, size of area). I suggest you sketch out the idea, make a small map and fax it to an authority who could give you better guidance. If you do a web search for Eruv you can get some basic guidelines on some sites. Good luck.