Check the city/township website under the link to the assessor or treasurer. A lot of them have online records. If not then call the assessors office and ask. The phone number will; be on the website. Best of luck!
You can also call the city or township and ask for the Assessor's office. Not only can they tell you what the current taxes are, they also can tell you what your new taxes will be if you pay X for the property. Depending on how long the person has owned the home, the taxes could be higher than what is posted.
Try the Wayne County Treaser site and click pay property taxes online http://www.co.wayne.mi.us/treasurer.htm Put in the property address. However, this will be for Wayne County. You may need to check your county public records, or give me a call and I may be able to help with your search.