Hi I just got DOSbox on my machine and I need help to learn how to use. I think it should be useful to point out that I know how to use DOS (I was stuck just using MS DOS 6 for a week last summer).

Where are you stuck? What are you trying to do and where are you getting problems? The commands should be the same as on real DOS.

start with setting up a drive, like "c:"
say you got some programs or games in your user's home directory
so the command to mount that as a drive letter would be at the Z:\> prompt
note how c has no colon.
to change to drive c: you would do it just like you would in dos:
and thats all.
use cd command to change directories and dir to list files.
for .exe, .bat, .com files you dont need to specify the extension, just like in real dos.
type "intro" to see the keyboard shortcuts for dosbox control and other usage information.
other than the mount command its just like the real thing.
let me know if you have any usage questions...
as a note, in my window environment (xfce4.4), the keyboard shortcuts dont work in windowed mode, much like they dont work with wine. in my case i have to control dosbox from fullscreeh mode. ALT+ENTER to get into the fullscreen mode does work actually.
good luck.