Step by Step: From no experience, to crossing an ocean:
Even before you hit step one, I recommend you tell no one! In my experience, most people are terrified to pursue their own dreams. To make themselves feel better they will try to hold as many people back with them as they can
1. Get a book on sailing. I've listed some that I have found useful here.
Time frame for step 1: a weekend or two.
2. Get a small sailboat. 15 feet or less? It's up to you. You just need to get your feet wet. Learn the basics on a boat that doesn't cost a lot. A Sunfish is a very popular, fun boat to sail. Start looking here: Craigslist.com
Time frame for step two: One month.
3. Get a sail boat with a cabin. Twenty five or Thirty feet. The purpose of this boat is to take some longer trips. Learn how to anchor for the night. Learn how to sail all night. Learn what it is like to be on a small boat. Don't let the small size fool you. Many people have sailed around the world on boats less than 30 feet long. For example, The Contessa 26.
Time Frame for Step three: A year or more.
Step three is the last step. Sail the boat as far as you can, as long as you can. You will always want a larger boat, but keep in mind: The boat you have now, is the one you can cruise in now.
Buying a bigger boat means you need to save for it. Which means you cant go cruising in the boat you own now because you are busy working so you can buy the next boat!
For other opinions on this line of thinking, visit this forum: go small, go now.