When you choose software for word processing you should first think of what you
will most likely be using it for. Will it be used mainly for just writing the
occasional letter, preparing a CV, writing a novel or to be used in a business.

The first word processor you will probably encounter is the Notepad, a mini 
word processor on the Workbench disk. It doesn't have a great deal of features,
but you can write a decent letter and prepare a CV on it, depending on what 
type of printer you have. The notepad may be the only word processor that you
need.

If you wanted to experiment more in word processing you could try one of the
packages in PD, although I haven't used a great deal of word processing
packages in PD. I have come across two that aren't at all bad, TextPlus 2 and 
Wordwright.
TextPlus 2 is very easy to use and all the commands are in menus and it uses
standard Amiga printer drivers.