For starters you can do a couple of things. One start saving. I travelled around south america for 4.5 months and it was brilliant. Spent on average 1200 per month, which included accomodation, travel, food, tours and excursions etc. some places (like bolivia) are cheaper than others to live/get around (like brazil). i met some people who had finished college and got around the world without working on 20K excluding their round the world air ticket.
secondly plan a route, what would you like to see, where would you like to go etc. etc. the world is huge and you cannot do it all in 1 year.
would love to do it again and i keep applying to middle abbey street for finance every week but no luck with application so far!!!