Depending on the length of your layover, it is not far to Windsor, which is also pretty cool.
If you remain airside, follow the Flight Connections signage (I think they're purple...I nerver pay attention) to transfer to T5. You will not have to re-check your baggage - just make sure it's tagged to IST. I transferring terminals, you'll have to reclear security again...something to keep in mind if you buy any liquids after security in DFW.
Have a good trip!
robin