Getting Started with Rails - Encountered beginning problem

Hello, I bought a book called "Head First Rails" and it's great,
starting off with giving me a few commands to instantly begin diving
into learning Rails. However, I ran into a problem that I'm not quite
sure how to fix.

So I'm following along the beginning exercise where I did the
following commands. Btw, I'm using Windows 7 cmd.

rails tickets
cd tickets
ruby script/server

Now, step 3 works and I can even go to http://localhost:3000/ to look
at some randomly generated Ruby Introduction Page, but I can't type in
cmd anymore. The output looks like this

This is completely normal. You can't type a new command in this
console session because the previous command is still running. You can
either kill the server or open up a new command prompt or run the
server in the background (with the -d option)

Fred

This is normal behavior
With the ruby script/server command you actually started a web server process.
Now that process is holding your console (the Windows 7 cmd)
So you should start a new console and you can type all others commands. In the first console, you can watch the result of the server operations

by the way, this book is excellent !!

good luck