First impression was “Wow, GUI looks better than 1.1”. Since I extensively use styles while creating design documents, I tried to define/modify styles (actually modify existing one) and keyboard shortcuts.
Choose Format >> Styles and Formatting >> Paragraph Styles >> Header x >> Modify
Style modification form pops up (Shown in figure below, I will refer to this form many times). A style has many properties (like font, alignment, position etc.) which can be set to desired values in the form.
In the same form, I was hoping to define numbering and keyboard shortcut for each style, but could not do it successfully.
After spending few minutes, I figured out how to define keyboard shortcuts for styles. Choose Tools >> Customize >> Keyboard. It turns out that OpenOffice.org by default assigns shortcuts to Header x styles (Control-x to Header x), which is fine. However style modification form does not seem to have a way to link styles with keyboard shortcuts.
However, for numbering it took me whole afternoon (3-4 hours) and still could not define numbering for each styles.
Eventually I found that style modification form is not the correct place to associate outline numbering with styles, even though form contains tab called numbering.
The correct place is Tools >> Outline Numbering as shown in the figure.
So important question is why can't style modification form have some way of specifying style numbering? There seems to be some issue with this, interesting details are in issue database issue number 5038. I wonder if I can take a look at relevant part of source code and make sense of it.
The outline numbering is also used to generate table of contents (choose Insert >> Indexes and Tables).
Now I wanted to save modified styles and use it for all other documents. This can be done by defining templates. Choose File >> Templates >> Save under suitable template name. To set the new template as default template choose File >> Templates >> Organize.
On my first day of using OpenOffice.org 2.3.0 writer, I managed to define styles as I want and get started and play around with other features. Although it took me some time to figure out style numbering and found some related issues (unless I am missing something).