Look at the cisco certification path. You can use the same study material even if you do not actually attempt to the tests. The study stuff for comptia is ok also but it does not go nowhere near the level of cisco. The key with the certifications is not so much getting the certification it is that it provides a structure to making sure you get a full understanding.
You do not want the braindump stuff. That is for people that want to get a cert by memorizing the test questions not by learning the material. Most the books from cisco press are very useful but you will find lots of stuff for free if you search for the topic CCNA.