Bonsai & GTD help

Hi.. my husband & i have decided we like Bonsai and are anxious to get started organizing things.  I have listened to the GTD book on CD & also actually physically read some chapters over.
 I thought i had a pretty good idea of the thought on taking everything out of your mind & put on 'paper' or a system.  I've started to do some in Excel spreadsheet, anxious to put it on the computer- finally settling on using Bonsai.  I saw the screen shots on Natara's website & thought it would be pretty easy/self explanitory.  I have read a few people's websites w/tips and downloaded this manual: http://www.simpleproductivityblog.com/files/Using_Bonsai_with_GTD.pdf

Now i'm a little confused.  I thought the basics were to set up contexts which i thought are like categories?  In my mind, I thought i would just be creating 'lists' under the different contexts/categories. Then i start reading the SimpleProductivity manual & look at Bonsai... and you have to start off with an Outline?  SimpleProductivity also uses Focus Areas. (which i like the idea because i do like merging Franklin Covey with GTD)

My questions:
-What is the outline part on the left side of the screen?  ...how do you set this up/organize?
-any suggestions for just starting off w/Bonsai & how to start off?
  --i have about 9 context/categories (the traditional "@" contexts plus a couple additional ones mostly used to distinguish contacts.
 -I want to use Bonsai for everything.. keeping track of customers i want to call, Spring Cleaning checklist, books to read, DVDs to watch, household projects.. just about everything :-)
-anyone have any good templates? or screen shots?  :-)

thanks for any help!