Nikon d3000, light graffiti and shutter speed?

I'm curious in everything for this - I've never done this before and I wanted to try it, some websites just tell me I need tochangethe shutter speed and to use a flashlight or a glowstick, but I need more. What should the shutter speed be on and how do I change it? What mode should the camera be on why I try this and how do I change the mode so it is continuous while I have the selftimer on? Help please! I'm really interested in trying this and I can't find good answers anywhere! Also, if there are any very good videos out there to help explain, please send them!

First about the shutter speed, read your owner's manual details are there. This being a dslr you should already know how to operate the camera but since you apparently don't, read the book.

I shot this in my office at night. Camera on a tripod. I used my 10-second count down so I had time to get in front of the camera. Shutter speed: 5 seconds - the room was completely dark. Since it's very difficult for any camera to focus without light I used the same flash light to light up an object where I was going to be, turned off the auto focus and did probably 20-shots to get what I wanted.