Arguably the very first thing that needs to be done is to freeze the feature set, as it were, and define a version 1.0 once I'm confident it's got all the glyphs for words and character combinations for a first pass.
There are several technical considerations after that. The letters need to be written by hand and scanned.
But I also need to establish a way to represent them in printed text; currently I have a large number of bitmaps that I made from editing a fixed-width pixel font. This may or may not be the best way. Obviously a full featured typeface would be best but that might be beyond my abilities.
Second there's the question of how to compose the documents; whether to put together a PDF document or a navigable website.