Follow in my steps.
0. Get really excited! :) I am.
1. Join the freespaceships google group. That is where we will try and solve the problem set we need to chew through to get off planet.
2. Start up a gmail, a blogger, google+ account, and facebook, we could use these sites to create our social network.This will be our communication hub. It will enable us to organise ourselves locally and globally. Efficient communication is just as essential as efficient handling of funds.
3. Get active: Use your head and figure out what we need to do, then if nobody is doing it yet, start doing it. At the moment number one priority is to grow the crowd. The bigger the better. We need a lot of people so the one hour "work" here and there each can spend on this, will add up to millions or hundreds of millions of man hours and we can get stuff done. Also it is essential for funding the project to have a large amount of people involved and willing to chip in with their pocket change.
4. Start saving: create your own space fund. A jar or a piggie bank will do, and any pocket change you can spare for this will help. At the moment we neither have the amount of people nor the system to handle the funding process that will be essential for our program. If enough people do this, we could move serious amounts of money towards the key projects to get the price of accessing space down.
5. Stay active: never give up. There is always more science and engineering that needs to be done to do more exploring, more colony development. We could enter a second stage of a growth phase necessary for interstellar expansion. Getting into orbit and colonising the solar system is only the beginning, we will have a whole lot more to do after that.