Many people, especially when starting out with a new language, are eager to get a “native speaker†to teach them. While you will eventually want to be able to communicate with native speakers, having them as teachers is not always desirable.
First of all, you are a native speaker of your own language — does that mean you know how to teach it? Where do you begin? How do you communicate the structural patterns of your language? Do you know what will be most difficult to learn coming from another language? Being “native†does not mean you know the first thing about how to teach your language.
In many cases, having a teacher who learned the language you want to learn as a second language is preferable because he or she will understand the stumbling blocks. Such teachers have figured out how to communicate the conceptual difficulties of the new language, and are therefore better able to help new students get up to speed quickly.
If you want to use native speakers as teachers, then it's good as the student to know how to get the most out of them as resources. If you know what you are looking for, you can tease a lot of information out of a native speaker in a very short amount of time. Native speakers are great resources. This requires a good bit of knowledge and experience on your part, however, and is particularly difficult to do when just starting out.
When looking for someone to help with a language, it's good to find someone who can quickly and clearly explain the complexities of that language in a way that's easy to understand. Unless a native speaker has undergone training to do this with his or her own language, he or she might only have value to you as a conversation partner once you've learned enough to get by.