I'm new to MMORPG's, but chose to take the plunge with FFXI, and I've not been disappointed. It's a wonderful game, and quite frankly addicting, if you can afford the time it takes to invest in playing.
Being completely new to the genre, this guide was a must for me. It has good details on early quests and missions, and though the maps could be larger, for many places you can get or buy maps as well in-game. As every monster is somewhat different, I found the monster guide fine, as it gives me an idea of what areas I can go to and which ones I can't, before I spend 30-40 minutes walking there in game.
The reality is that all of this information can be found online. Often it is better info, such as maps of NM spawn areas, etc. However, I find the guide invaluable, and it is always by my side for a few reasons.
1)I do not want to run back to the auction house to see if it's time to upgrade my gear. I check the book, and go back when I reach the appropriate level. The guide also details the gear itself, saving me considerable time looking when I do get to the auction house.
2)If you don't have another computer right next to the one you play on, it's mighty hard to check quest and monster information while you play. Having a printed out book to flip through is wonderful. The book is quite clear on what you need, and what you get, so you can easily do the quests with the biggest rewards and skip others.
3)It's true the synthesis guides are short, but they are intended to get you started. At low levels they are wonderful to have at quick reference. Once you get higher level in your crafting you will be relying on other player formulas more extensively.
4)The job information is extensive, including the abilities and levels they are gained per job. This has been an invaluable resource as I plot my main job and sub job path within the game.
In summation, this book is a great reference for some things, and nice to have handy. For higher level players you might be better served by forums and websites, but even then there are some things such as gear lists that are nice to have at hand during the game, unless you want to print out page after page of often poorly formatted websites.