Under the file tab, choose the name of the output file and where you want it to be saved to.  I dont mess with the general Tab.  The Defaults work fine for me and I dont use Divx 4.0 because it is too slow and the quality is not as good.
 

           

Now you are done with the Global project output file tab.  Before I go to any other tab, I break out the Bitrate calculator.  This is a really cool tool.  First choose Divx 3, which is what we are using, then choose the movie length which is 147 min or 2hours and 27 min.  Choose you audio bitrate and the 25 fps that we specified in the Global Output settings.  Choose the desired length of the movie.  With a movie this long, 900 megs is a good file size, but you can make it smaller if you wish.  You will lose some quality though.

Hit "Enter" and you have your bitrate.