The field of immigration includes many imposters — “consultants,” “notarios” and others who offer legal advice and fill out forms for people without fully understanding the legal complexities involved in answering even a single innocent-sounding question. What you need is a licensed lawyer who has passed the bar exam and has been admitted to the bar association of at least one US jurisdiction.
Since federal law governs immigration, it doesn’t matter which jurisdiction your immigration lawyer is licensed to practice in, as long as it is US state or possession, territory, commonwealth, or the District of Columbia. As long as the attorney holds a license in one of these jurisdictions, it doesn’t matter exactly where. If you live in California, for example, and your attorney is licensed to practice in Idaho, for example, the fact that he is not licensed to practice in California won’t matter.
Of course, saying that someone is an immigration attorney is a lot like saying they are a physician — just as some physicians are a lot better than others, some attorneys are a lot better than others. You should also pay attention to specific areas of practice. Is the experience of the attorney limited to employment visas, for example, family-based petitions, deportations/removals, or some other area? It matters.