Recipes stored on the Grainfather site (dislike the new interface though), inventory spreadsheet in excel which also has my planned brews and past brews recorded just as an ingredient list. Then I have a small general purpose notebook which I'll note down the recipe in for weighing grains and expected gravities and volumes and will make notes on the day of how things compared. Finally, I have a A4 hardback notebook which I record everything in as a full log with tasting notes for the future. I could probably do without the log book, but I like handwriting things as I enjoy finding any excuse to use my fountain pens more, also without it I'd have to record more information on the GF site which I don't like using except as a recipe builder.