Do you mean how many sets a day? If i was starting off, i would say do 3 sets of 10, with a 10-15 second break and take it from there. If you can do more complete sets carry on. Ideally, the 3rd set should be a real struggle to complete. If you do not complete it, thats good, as it gives you something to aim for next time you do it
As with any major weight lifting exercise where you want to build muscle, you need to give your body time to recover.
So for best results I suggest that you do not do these the same day that you cycle, but it all depends on your body and how fit/strong you are.
I am no expert on this, but have picked up things when doing the gym.
I am finding that some hills on my commute are challenging, but they are not as extreme/long as yours, so I am just going for it and bearing the pain