The start menu is the ubuntu symbol typically on the top left

Although on Ubuntu 10.04 it is the smiley face in the upper
right panel a single click and it will be a drop down list.
Next to is the name of the machine.

You can edit the menu by right clicking on the Ubuntu icon (top left of the
screen) and choose Edit Menus from the drop down. If for some reason the top
panel is missing you can add to the bottom panel by right clicking on the
panel and choose Add to Panel. The "Start" button is called the Main Menu in
the choices of things to add. You can remove the top panel entirely (Remove
Panel) and add icons to the bottom panel, including a "Start" button, so
that it works more like Windows. You can also add a panel (New Panel) if one
is missing. You can have them on any or all sides of the screen. Typicaly
you have to right-click on a blank area of the panel otherwise the choices
change and are for that panel item only.

Not all Linux distributions work the same way, but all can be changed to
suit your purposes. The GNOME desktop environment which is used by Ubuntu
typically has two panels with the main one at the top. I remove the bottom
one to save desktop space. Linux Mint, a distribution based on Ubuntu, uses
only one panel at the bottom in GNOME, so that Windows users feel more at
home. KDE which is another desktop environment entirely has one default
panel at the bottom. I move it to the top so that I can put the Avant Window
Navigator panel at the bottom so it look more like a Mac. The bottom line is
that Linux is very configurable because unlike Windows it is not locked down
and is open sourced. Microsoft wants a universal look and feel which is
understandable since it is proprietary.

If you are still confused, please ask more questions. The users here are
great and very helpful. No question is too dumb and we all started out in
your situation at some point in the past.

Thank you for both of your replies. What I am looking for is the path. I have
the icon: that is how I use it now.

There is no single start menu as such. The panel that appears by default at the
top of the screen has a number of drop down menus that offer between them
everything the Windows start menu does and more. The Ubuntu symbol at top left
is the Applications menu. The symbol at top right (mine looks like a power
switch rather than a smiley) has logout, switch user and shutdown options.

To get to a command line go to the Applications menu, then accessories, then
terminal. (There's a hotkey to get there too but, unusually for me, I can never
remember it). You can drag Terminal from its menu and park it on the panel (next
to the Firefox symbol, for instance) if you're going to use it frequently.

To alter the contents of the menus, choose System > Preferences > Main Menu.

But reading your message again, I think you're asking how to use the CLI to
reconfigure the menus? Can't say I've ever seen that done. Being *nix, there
must be some text files somewhere that you could edit, and no doubt someone will
know where. For instance

www.uluga.ubuntuforums.org/showthread.php

seems to suggest that /usr/share/applications contains ".desktop" files that
make up the menus.

To change the menu, run Preferences/Main Menu.