www.tripadvisor.com
TripAdvisor has an alert that sends you an email when the prices to your chosen destination drop below your selected amount.
Do everything early. The prices of flights to different airports fluctuate, so find out which season is cheapest for your destination. Research hotels, cities, maps, and create a schedule detailing your plans. But keep things simple... don't try to fit too much in your travel schedule. Since you're alone, you'll want to stay in the safer areas, so look into that as well. Don't carry too much luggage. Less is more. Only take the items you need the most.