One half of the pages will drop in Angmar and Eregion, the other half will drop in Misty Mountains and Forochel. Unless you wait until Moria (which drops all the pages) you'll have to use more than one zone to get all the pages.
It's split by top half and bottom half (as shown on the deed) but I don't remember which is which.
If you want to leave two legendary slots open until you can get there that is ... When I first got rain of thorns on my hunter it made life/pulls much easier.
I'ed recommend that you keep questing in Angmar until you have the first four pages on each of your legendarys skills, if you run out of quests there's always the slayer deeds (Angmarim slayer +1 Justice or +1 Zeal from Orcs anyone?)
Then just move to Mistys or/and Forochel and start questing there, while collecting the last pages. If everything else fails you can still grind Goblins/Goblintown (bring friends :P) or the Bitter Stair in MM.
The traits are nice, yes, but I wouldn't bother grinding just for them, as I find grinding dull. Do quests in MM/Forochel/Angmar/Eregion and let them drop naturally. If you make it to 50 without finding them all, it's your choice, but I would (and have and will) just enter Moria and let them drop there.
A spaceship from another star / They ask me where all the people are
I tell them I'm the only one / There was a war, but I must have won