I think heavens above is the best. It gives you exact times, magnitudes, star charts and data about what you are seeing, when it was launched, etc.
When looking for a sattelite, remember the first minute or so that it is technically visible may be hard to see, as its coming at you from very low on the horizon and usually you don't have a full, unencumbered view. But when you get the ISS at a mag 1 or less, you really can't miss it if you are looking in the right place.
Thank you so much!