Shoes For My Sled???

Have a 1997 Taurus GL with 15 inch wheels. What is the bolt pattern for this car 4 1/4, 4 1/2 not sure how to measure. Also how much larger than stock can I go tire wise? Anyone with custom tires and wheels, can you send me a photo? Sometimes I see some nice wheels at the pawn shop but don't know if they would work and is there going to be a problem going from the 15" to maybe a 16"? Thanks for any help on this subject.