There are tons of them. I've read many of them. They all say the same thing.
I have only been cycling for a couple of years and have done lots of centuries, training for one is not rocket science. Especially for you, since as a runner, you are pretty in tune with what your body is telling you.
Here's what you do:
Start riding a distance that is challenging for you, but doesn't leave you totally trashed at the end. Ride that distance for a couple of weeks until it feels really easy. Then start increasing your mileage in 10% increments. Every time you increase your mileage, stick to your new mileage until it becomes easy. Then increase by 10% again, etc. Do this until you reach 75miles. This should be a couple of weeks before your event. Train on terrain that is similar to what you will be riding on for your event (ie, if there will be hills, train on hills). Taper your volume the week before the event. The week before your event, get your bike ready, eat well, stay hydrated.
As you increase you mileage, you will also be increasing your saddle time. Take this opportunity to figure out what works in terms of clothing (and position on the bike, if that may be an issue). This is also a good time to start paying attention to nutrition.
In terms of nutrition, you will be burning a lot of calories and depleting your glycogen stores. If you did much distance running, you may have dealt with this before. Basically, you will need food that you can eat while riding (easy to unwrap, and doesn't cause gastrointestinal issues). The food should have easily absorbable sugars, protein, and maybe some potassium and/or salt for electrolyte replacement. Bananas work well, and peanut butter, but these can sometimes be challenging to eat while on the bike. Alternatively, there is commercially available stuff like gu, hammer gel, shot blocks, etc. Try these out on your training rides and see what works for you.
I think that really covers what you need for training for a century. And by that I mean that you won't have a problem finishing the century. If you want to be really fast, then it gets a bit more complicated. But for your first century, I would just focus on finishing it, and having fun while doing it. I have met a lot of people of organized century rides whose longest ride before hand was in the 50mile range. They all finished, although not without some suffering. If you train up to 75miles, your century will be breeze.