Ancestors of Johann Ernst Schulze Born 27 October 1826

My Great Grandfather, Johann Ernst Schulze was born in Dessau Anhalt-Sachsen on 27 October 1826. According to my information, he emigrated to Russia sometime around 1850 inorder to avoid military service. He then returned to Dessau after a few years and took up the occupations of farmer and tischler. he married Dorthea Els sometime around the mid 1850's. They had three children before emigrating to Texas, USA, in 1860. I am told that his father's name was Johan Ernst Schulze Sr and his mother's maiden name was Maria Dorthea Voigt. I would like to find information concerning his ancestors for however many generations information might be available.
Also, I am planning a trip to Germany in 2006 and plan to visit the area of Dessau in Early June. I will probably have about 4 to 6 people with me. Where should I go to find information about my great grandfather's ancestory and any information about possible places to stay would be appreciated. Thank you very much for any information that anyone might provide. Best Regards, Eugene Voelkel, 4 Ravens Perch, Bryan Texas, 77808.