I have practiced on and off for about 10 years - my heart always brings me back to the craft - i am currently working out of an old book of shadows but i feel its time for a change - there are many things in the old book that i want to change - i want to organize it more and have the important things in the beginning - i want this to be a book of shadows that i pass on to my daughter if she wishes to practice - so with that i have 2 questions:
1) after i start my new book and i'm fully ready to let the old one go, should i save it or get rid of it
2) if i get rid of it what is the best way?
I am not aware of any "traditional" way to part with a BoS.
In my view, It's up to you to decide if you keep it or not, and how you treat it if you don't.
If you decide not to keep it, you could destroy it ritually:
bury it if it is fully biodegradable, to give back to Mother Earth for all the magic she has given.
Or burn it to set its energy free for new creation.
Make an origami swan out of every page and trust it to the water, so it can return to the Source page by page.
You could recycle the book yourself into hand scooped paper you can use for new spells.
There are probably a dozen more ways to say goodbye to your book.
The important thing is that it has been yours and that you part with it in a way you are comfortable with and that honors the magic it contains. Don't just throw it in the trash with the old newspaper.