I'll give you the quick and dirty version and then it's up to you!
#1. Write something - a short story; an idea for a book (a chapter/chapters); a poem; JUST WRITE IT. You've probably had an idea or two percolating in your brain for a while now, anyhow. Start there. Always write in 12 font, New Times Roman, double-spaced. Use your tab key for paragraph indentation.
#2. Find a local writers' group to join and learn the basics as you get your work critiqued by the group. Bring copies for the group. This part will take time, but you'll appreciate it in the long run. These are usually free and they're way different than book clubs.
#3. Find training events to attend, i.e., conferences, seminars, workshops. Joining a writers' association, such as the Pacific Northwest Writers Association, helps you find them. Expect to put out some cash for this part.
#4. Leave your ego in a safe and secure location. You won't be needing it for a bit. Prepare to get chewed up and spit out. Rejection's just part of the reality of writing.
#5. Your first published work will usually take 145,615 times longer to see on the market than you originally anticipated. Then you can take your ego out for a short walk before putting it back and beginning the next manuscript.
I don't want to get into the marketing aspect for fear you'll fry a circuit. That will come soon enough.
Is it worth it? Not if you're looking to earn your fortune or want to quit your day job before you retire (unless your one in a million number comes up). Otherwise, yep, it's worth it. Good Luck!
BUFFALO HUMP was two and a half years in the making before it was published in December of 2012. I was my third manuscript.