Heros Handbook question...

It says, on guildwiki, that you can turn in a handbook at any point to get faction and money, but the ammount will be less depending on how many quests you have done. My question is, if you turn it in part way full, and later on finish the book, will you be able to retrieve the faction an such for those parts of the book?

no, once you hand in a book you have to start a new one to get any further faction.
so if you hand in a 3/4 filled book and then finish the last 1/4 you will still miss out on the extra gold/title points you would have gotten if you handed in the book while it was full.