You do NOT have to buy the Anaheim book, and since it's one of the more expensive ones, I wouldn't recommend it. My region's book without a discount is $25.
If you go here you can see all the books:
http://www.entertainment.com/discount/local_editions.shtml
Since they are all equal with the travel discounts (my south-of-seattle book even has Universal Orlando, Seaworld, and Super Shuttle coupons, among tons of other nationwide coupons), you can see that buying the Anaheim area book for $30 right now would be a waste since you could buy the Alabama book for $15 and get the same useful card for HoJo's discount.
I know that in my area, the chain-restaurant coupons are for specific locations.
Looking online at the OC book, I see Wendy's coupon, but it's only for E. 17th St. Costa Mesa, CA 92627, not ANY Wendy's location.
I see many McDonald's listed, but not the one on Harbor.
I see some Burger Kings listed, but each coupon has a different location listed.
I'd just buy the cheapest, personally.

And if you're a part of any of the "rewards" sites like Sunshine Rewards, buy through them and get a bit of credit back! (that's what I did)