Virtually all travel guides and brochures will have suggestions on places that you can stay at your destination. They do this because you are obviously going to need to arrange for a place to stay and you are likely not going to have a lot of information on which to base this decision. For the most part these guides will offer advice that should allow you to find a hotel that will meet your needs so that you can be sure of having the best possible trip.
The main reason that people like to use travel guides for suggestions on hotels is that they are far more likely to provide you with objective advice. Of course this is far from always the case. Most people get their information for their trip online, the problem with this is that whenever you get any information online you really have no way of knowing who put it there or why. When it comes to hotel rooms you can actually be pretty sure that the information was put there to earn a commission from the hotel booking. This doesn't necessarily mean that the information is bad, if the commission comes from one of the large travel sites they get paid regardless of which hotel they book at.
Since most people are wary of the information that they get from the internet they tend to put more faith in the information that they get from travel guides when it comes to hotels. This is not always a good idea since it is always possible that a hotel paid the author to be included as a recommendation but this is fairly uncommon. You can usually be confident that the information that you find in the guides will be good.
One of the other reasons that you are going to want to use travel guides for information on hotels is that you can at least be fairly confident that the author has at least been to the city that he is writing about. This is not something that can be said about the internet. People may create a site about a certain destination even though they have never been there. This doesn't mean that the information is necessarily bad but you do have to be aware of the problem.
While travel guides and brochures can be a great way to get information on hotels at your destination when it comes time to book them you are probably going to want to do that online. In general your best bet will be to use one of the travel sites that allows you to compare the various options that are available rather than just booking directly with the hotel that is recommended in the guide. This is almost always the way to get the best deal, even if you do end up staying in the recommended hotel.