Basics:
1. set port pin(s) to output mode so you can control the LED
2. configure a timer, TMR1 would be best choice in your application because it has 16 bits so can be used to create longer delays.
3. configure the source to the timer, internal clock or external clock and set the pre-scaler to a suitable divisor.
4. timers count UP and it's easiest to test them for rolling over to zero after maximum count so work out a value to load for the number of counts before roll over.
5. either poll the timer, looking for zero or better still, enable the timer interrupts so it jumps by itself to your interrupt code when it reaches zero.
Long delays like one minute may not be possible using a single roll over, you may need to use a software counter to count the roll overs until sufficient time has elapsed. For example, use 600 * 100mS counts to make 60 seconds.
Brian.