If you use Word for creating/editing the files, store them in RTF format. I have found it the best interchange format. (Word creates a very, very bloated HTML file that is best to avoid at all costs.)
Then you have three choices:
- Load the RTF to the Sony
- Create an LRF file in Calibre
- Create an LRF file in Book Designer
If you do #1 you lose all graphics you may have in the file and it does create a rather large footprint inside the Sony.
#2 is a great choice and you can do a load and go. Calibre also provides for the creation of ePub files. Calibre is used by Fictionwise to create all of their LRF format books they offer for sale. There is also active Calibre support at MobileRead.
#3 (Book Designer or simply BD) is also a great choice although it has not been updated in over 18 months. (Calibre gets updates frequently.) The set-up for BD is a bit awkward and there are a lot of us around that can help. Once past the initial learning curve it is a very easy program to operate. I have used it for most of the books I have posted in the MobileRead download section.
Why create LRF or ePub files for the Sony. Three reasons -- speed, features, and size. LRF and ePub are the native format of the Sony (LRF) and the emerging standard for ebooks ePub.) They render faster than many other formats. Both LRF and ePub allow the inclusion of a TOC, graphics, footnotes, chapter titles, page breaks, and extensive meta data. Most of these are not available in some formats. Both are also compressed formats and take far less space in the memory of the Sony thus allowing you to store more ebooks than you could with some other formats.
When I started with the Sony back in 2006 Book Designer was all we had. If I was to start today I would learn Calibre and forget about Book Designer.