All it takes is critical thinking.Here is something about the guide system in the game (coming from someone who had never played a moba before and is still learning a lot about the game):
It doesn't teach you shit. When I first started playing last year I was looking up builds on playdota and learning about the characters and why go a certain skill/item build might suit different situations. Now it's just "oh thats what the highest rated one says so I do it".
Don't get me wrong, it works really well for when you are trying to just learn the mechanics but when you really want to learn how a character works it doesn't help with that at all. RIght now I am trying to get myself to stop using the guides because I feel they are hurting me overall.
Just ask yourself - why are they buying x or levelling y. And I assure you, you will learn faster with a guide then blind on your own