Can nikon d5000 do hd video?

If so how?

It can do HD video (720p)

If you want Full HD video (1080p) the Nikon D3100 is the camera you want. It will also auto-focus in the video mode.

If you already bought the D5000, look on page 50 of your user manual

Yes. 720p. (480 is standard definition; anything above is high definition - including 720 and 1080… And "ultra-high definition").

http://www.nikonusa.com/...D5000.html
In "Movie" capture mode, by capturing light through the lens, allowing the light to hit the imaging chip (which digitizes the data), sending it through various electronics in the camcorder and writing the video file to flash memory.

Yes, it can shoot 720p HD video but you have to manual focus. If d5000 shares the same method of shooting video with d90, hit the live view button and press ok to start shooting video then ok again to end.