Screenwriting was my passion at Uni. I've got a hell of a lot of resources if you ever need anything such as movie scripts (Aliens, Pulp Fiction, The Dark Knight, and many more). Also I recommend a book by Ray Frensham called Teach yourself screenwriting. He speaks a lot about the pitch and the harshness of the industry besides the Writing itself. It's very well balanced and has been my Screenwriting bible for many years. Sounds exciting but like you say it's a long process with intense financial scrutiny. The good thing about adaptations is they are financially viable compared to the newbie screenwriter. Storyboarding is much easier. They essentially have a treatment to work from already. Lots of companies are playing safe at the moment so for you to be approached is deffers a calling card for the future, however long it may be.