I'm doing a similar thing, but going the other way, down to South Africa, across to Rio, up to San Francisco, then across to singapore and home overland through india and eastern europe. I found this site very helpful, but I have found that I have planned much less than I thought, I'm leaving in early Jan. My line of thinking is that it is an unknown quantity to me so I have no idea how long anything will take to accomplish or how long I want to stay in places. I think if you have the freedom to do it this way, give it some thought, I would hate to be tied down by deadlines and dates. But of course if you are limited on time, then you need to plan much more in advance, some food for thought maybe! Good luck!