What is a good route to a writing career?

A successful and working scriptwriter I knew once told me to watch TV programs and write follow up episodes. Once you become proficient, send them to the producers. Other than that, write short film scripts and seek funding. You could even try to team up with people who have the ability to make the film and enter it into competitions. Check out film schools.

Study hard to find a job that will earn you steady income (not necessarily writing related). Then start saving money, so that you can work part time at some point. Then use the free to time for writing. Only a small percentage of writers can earn a living from writing.

This book is excellent. Don’t let the goofy cover fool you.

In line with what Matt said, have you ever seen the movie The Player? It depicts screenwriters as pawns of the movie studios, which will buy up far more scripts than they ever plan to use, in part to keep other studios from having the rights to them. I don’t mean to discourage you, but it would be a good idea to have a Plan B to fall back on.