My external flash on my Nikon won't fire?

I'm using a Nikon D5000, and i just purchased a Zeikos SB-700 external flash. I read the manual and the only instructions it gave me were "when the Ready Light lights up, the flash is ready to fire. Pressing the Test Button will test fire the unit. 1) there's no test button. 2) why aren't there instructions on how to make the flash fire when shooting.
so anyway, how do I make the flash work, I feel really dumb, but I can't for the life of me make the flash work, is there a setting on my camera i need to adjust, is the flash broken, like a shorted wire or something that won't let it work?

Try this.

http://keerok-photography.blogspot.com/2012/08/how-to-use-generic-flash.html

Are you positive that flash is correct for your camera? It may not be. You can't just buy any flash to fit any camera, it doesn't work that way. Read the manual again and see the makes and models this flash works with. If yours isn't listed you bought the wrong flash.

I bet you bought the Zeikos cos it was cheaper than the Nikon.
Now you know why.

These cheap Chinese copies are a total waste of money. Take it back where you bought it and if they can't show how it works get your money back and buy a Nikon unit.

Flash units are the one thing that I never recommend cheaping-out on and buying 3rd party. And if insist on doing so, buy a good flash unit like those made by Metz.

You did not state if you are using the camera in Auto mode or one of the PSAM modes. Realize that in Auto mode, the flash will only fire on the camera when it thinks it needs the flash. That means the flash unit may not always work, but depends on the camera.

So to test this theory, put your camera into one of the PSAM modes, and see if you can get the built-in camera flash to work. When you can successfully do that, then put the Zeikos flash on the camera and see if it works.

Also, the cheap of the cheap flashes may only do manual; which means you may have to put the camera into manual mode, then calculate the proper exposure. Flash units used to have an exposure wheel to help you do this, but these days, you may on ly get a piece of paper.

You can confirm if the flash is a manual flash by turning the flash over and looking at the contacts on the hot shoe. If there's only one pin sticking out - it is a manual flash.

Unless you are experienced at doing manual exposure with a flash, you will quickly tire of having to experiment with the flash to get a good exposure. You may then want to consider buying a Nikon SB700.

I have a Z6 and a SB700 - the Z6 will not fire the AD200 with a trigger like my D750 has for years, NOR will it fire the SB700 again which my D750 has for years. What am I missing?