A lot depends on how old you are and your general athletic condition.
The older you are, or the poorer your athletic condition, the more you need to "work up" to a longer ride. The worst thing you can do is hit it hard right away, and end up with knee or ankle injury that will slow you down.
Next time, ride for ~1-1/2 times as long. So if your 10-mile ride took 40 minutes, next time ride 60 minutes. Do that a couple times. Then extend to 90 minutes, do that a few times, etc. After 5 or 10 rides you'll understand your limits better and can plan accordingly.
I'd stay to the flats for a while, until you get comfortable with your limits.
Make sense?
Tired or sore muscles are one thing, but if you notice some knee or ankle pain, be careful... back off a bit and/or consider slight adjustments to your riding position (seat, bars, etc). Don't be shy about getting some bike fit help from the local bike shop.
Many of the folks on this board are VERY serious and VERY experienced cyclists who have been riding for years. Comparing their workout to yours is kind of like asking Tiger Woods about his golf practice...