There are several ways you can find out about the countries and places you wish to visit. You can talk to friends who have traveled to the places, you can go and see a colour film about them, or you can read travel books.
It seems that there are three kinds of travel books. The first are those that give a personal, subjective(主观的) idea of travels which the writer has got himself. These books can be useful if the writers share their traveling experiences with others. The second kind are those books which give objective( 客观的) information of things to be done and seen. If a cultured person has written such a book about the facts of a place, then it is more useful. The third kind are those books which are called "a guide" to some place or other. If they are good, they will describe and explain the place in detail. Like the first kind, they can be interesting and exciting, but their main purpose is to help the reader plan his travel in the most practical way.
Whatever kind of travel book you choose, you must make sure that the book does not describe everything as interesting, exciting or fantastic. You must also keep an open eye on its date of publication(出版)because travel is a very practical matter and many things change quickly in the 21st century. Finally, you should make sure that it's easy to find the useful information for your travel.