Lost

I have been training on and off for two years. I was backpacking through europe and basically drank way too much. Anyway I’m about 200lbs and 6’1" I have body fat % of 18% (ouch) Anway. I want to stay at 200 lbs but cut the fat % and build muscle what is a good way of going about this and is there a diet that can help.

FYI yes I won’t be back packing through europe anymore as I am now a full time student and therefore have access to a gym. Would like to go to a personal trainer but can’t afford them. Thank you.
P.S I hate the beer gut

Read this:

http://www.t-nation.com/readTopic.do?id=640350