I noticed that the MetaMap NoteBook module does not have it's own keybinding. I also noticed that it got annoying having to find the minimap icon every time I wanted to open my notebook for Joana's guide to check my progress and what I had to do next. Well....I changed that
Here's the step by step method to creating your own keybinding for MetaMap Notebook
1: Go to your MetaMap folder. World of Warcraft > Interface > AddOns > MetaMap
2: Right click on the Bindings.xml file. Click on Edit, and it should open that file in Notepad. Insert these three lines of code exactly as I paste them here
Code:
<Binding name = "METAMAP_NBK">
MetaMap_LoadNBK();
</Binding>
It will look like this

Hit save!
3: Now, this step is unnecessary. The keybinding code is now in your WoW and it would work normal without this step. However, to make it look nice and normal on the Keybindings menu, go back to the MetaMap folder, and right click on the localisation.lua file (there are a few of them...the others end in .de, .es, and .fr). Again, click on edit. Scroll down to the second main section of code and insert this line
Code:
BINDING_NAME_METAMAP_NBK = "Toggle Note Book";
at the end of the BINDING listings. It will look like this

Again, hit save!
Enjoy your keybinding
It makes the in-game guide that much easier to use.
Again, props go to The Demon in you and Alth. They gave me the idea to do these step by step guides, because I noticed people were having difficulty. I hope these help! If you have any other questions, I will try to answer them as soon as possible. If someone else can provide an answer before I can, feel free! If there was any place I did not give credit where it was due, please let me know. Thanks