Okay, first off, cycling totally helps running endurance. Cardiovascular and muscle development, helps with breathing, but most importantly, an hour on the bike is an hour of exercise which will pay off when you want to get into longer distance running. It helps in so many ways!!
Secondly, a lot of pain and injury (shin splints) can be attributed to improper footwear. Get yourself to a running store and get the right pair of running shoes for you. Correct fit is important, but choosing the right shoe (stability, cushioning, neutral) is crucial. You'd be surprised how many problems can be erased by getting the right shoe for you. Don't be mislead, some shoes are more expensive but are designed for different runners. Don't buy something because it's more expensive. Get the right shoe - a $150 support shoe is worse than a $80 neutral shoe if you are a neutral runner. Getting the wrong shoe will give you pain and possible injuries for sure!!
But yeah, biking will improve your endurance, big time.
