There are no hard, fast rules in modern contemporary witchcraft, it is all down to personal preference, to fill a specific need to you. You could choose to use all three different journals, two or just the one. You may find you have multiple Grimoires as the information you collect over the years grows. You can have as much or as little in your books as you see fit, The choice is yours. Whichever you may choose it does not need to be fancy, but it will need to be sturdy and be able to open flat, don't be concerned about your handwriting or spelling as these are your own personal accounts I would suggest that you take your time writing your spells, make sure it's eligible so you understand what you have written when you refer back to it! Be true to yourself, you should never censor your Book of Shadows or Book of Mirrors, if skilled some may write in code, but if you censor it when writing, it will change the energy of the book which will dilute the power. Keep your Journals safe and private, even a lock is a deterrent as you will know if people have pried! Choosing Your Journals Again this is personal preference, you may chose to have a filing cabinet stuffed to bursting with notes and references, you can have a hard copy online, or a simple spiral notebook, a ringed binder or a scrapbook artfully put together, or a combination of everything! Personally I have a Grimoire ( or two! ) which is a simple ringed binder that I have organised into easy to find sections, my own magickal collection of useful information. I have backed this up in hard copy as well incase of forces beyond my control! A Book of Reflections, which is my dream and daily journal, and a Book of Magick which holds Rituals and go to tried and tested spells and magical workings. This is what works for me, we are each unique and what works for some may not for others. What to Include Magick has rules whichever path you follow, each group will vary and each solitary practitioner will have different ideas about what is right for them. There will be different ethics and moral codes as well, if you follow Wicca there is the Wiccan Rede, or a similar concept if that is not your path. All journals should include a title and the date, to help you stay organised, some Practitioners keep one big book and when it is full, some archive it and start another, some may start a new one every year at Samhain.