Online on their website, click on manage your booking and input your details and it will let you then give advance passenger information. You may be able to do it by phone as well, but i'm not sure. I doubt it.
Advance Passenger Information
The Electronic Advance Passenger Information System, or eAPIS, allows you to enter or upload passenger and crew manifests online.
The fare varies greatly on the time of year and how far you book in advance, therefore look at Ryanair's website for the prices.
Ryanair change their fares daily. The best time to book is around 2-3 months in advance usually; as this is when the sale tickets are available.
I think ask santa Claus
Check their website, as it often changes. I've attached a link below of Ryanair's route map which will give you all the relevant information.
I personally know a little bit about Ryanair, however I would recommend checking out the wikipedia article on Ryanair that i have attached below. It will give you more precise information.
Ryanair has 303 aircraft.
Ryanair was created in 1985.
No Ryanair is an Irish owned airline.
It is an airline company and is Irish .It is known for its low costs. The main office is in Dublin. It also has a guide online for passenger survival .
They frequently have ticket sales, and don't announce when. Usually the best time to book is about 3 months in advance.