Below are some references that have and continue to help us with the travels. Let us know if you have any additional ones to add:
Planning
BootsnAll Travel - This site covers everything from planning and tickets to articles, budgets, and insurance.
Gear
Amazon.com - They have everything.
Backcountry - Great gear, lifetime unconditional return policy (better than REI), free shipping on orders of $50 or more. They always match REI's sales. When you call them, a 20-year old ski bum in Utah answers. That sounds legit to me.
REI - Who hasn't walked into an REI and walked out with new gear and a lighter wallet? During REI sale events, stick with Backcountry.com, but during regular times, REI is a good option if you have a membership because you get a refund on your purchases.
Travel
Rome2Rio - Tells you how to get virtually anywhere by plane, bus, ferry, or car. This is the first place we go when we start planning our movements.
Skyscanner - The best flight searcher for flexible travelers: you can search multiple destinations, over an entire month, across different parameters, and you can change searches on the fly. The mobile app works just as well, and you can save specific flights to watch the prices. Prices are almost always spot-on, and the website doesn't take commission.
IHateTaxis - Before you arrive in a country or airport get a quick rundown on tipping, currency, electrical outlets, transportation options and more. A good collection of concise information, though information can be sparse for some locations and the website looks like it was made in the 90s.
Wikitravel - Information on destinations and how to get there. Better than Lonely Planet.
TravelFish - Excellent travel guide for SE Asia! We started relying on this site soon after arriving in Thailand.
CouchSurfing - Host someone at your place and crash at a stranger's when traveling. This travelers' network is one of the most useful sites on the Internet. I've hosted people for many years and am now starting to use it more as a traveler. We've met great people through this site and have saved a bunch of money.
BeWelcome - a more open, transparent alternative to Couchsurfing. Unfortunately, it has fewer members because it is newer, but with time, it will grow.
Other blogs
AlexToAlex - Rehanna and Julia are two South Africans road-tripping across East Africa with interesting perspective and stories. They speak with an eloquence that belies their background as journalists.
Nomadic Matt - this guy has been everywhere and writes on tons of topics. The articles are short, easy reads directed towards a traveler audience.