I will be the first to admit that Immigration Law is very confusing. Because of this you should be very careful about who you choose to help you with your case. Once you chose an attorney take great care to ask questions and make sure that you understand exactly what the attorney is going to do for you. While lawyers do have a professional responsibility to act in the best interest of our clients, not all attorneys will. Such a case recently occurred in Colorado. See http://www.cpr.org/article/Immigrants_Swindled .
An experienced and reputable immigration lawyer should be able to fully explain the requirements, the process, and most importantly the risks associated with filing immigrant or non-immigrant application. With all of my clients, I try to be as honest and upfront about my concerns. I also make it a point to make sure my clients understand the consequences of inappropriately filing an application or misrepresenting information.
In any event, please, please, please understand exactly what it is that your attorney is doing for you. As the saying goes, if it sounds too good to be true, it usually is.