I am currently using Karen Saunders' The Breadmaker Bible, and tend to have a look on the internet for other recipes.

However it would be useful to have a book that goes a bit more into how flour, yeast etc "works", to answer questions such as Is Spelt more or less absorbent than bread flour?  How much salt do I need?  Of course trial and error is fun, but this would help to keep the disasters to a minimum.

Is there such a book on the market?  Most simply run through the ingredients and then give you loads of recipes, which can be more or less easy to adapt.