Health (aka the boring stuff)

Hostel World Travel Insurance - Travelers health insurance

Trevelex - Currency, cash passport, insurance (less than 180 days), etc. (Experts at the boring stuff)

CDC - The most obvious travel health site

CDC Food and Water Risks - Advice on prevention of illness due to food and water

STA Travel Insurance - Probably the best long-term travel insurance out there

Insurance Policy Picker - Courtesy Lonely Planet 

Specialty Risk International - Travelers health insurance

Health Guide - A Lonely Planet straight forward guide to what you need to do