For me, it sort of depends on the game and type of guide. My guide for FFTA is battered and dogeared because I used it as a class/spell/weapon reference SO MUCH.

I also read this "Harvest Moon relationships walkthrough" on GameFAQs pretty religiously for a while when I got to the waifu simulator part of the game.

But I don't really like the ones that walk. You. Through. Every. Step. Of. The. Game. They tend to take a lot of fun out of the game, imo.