Planning for your first backpacking trip is fairly terrifying. The most valuable questions aren't what to do when traveling, but how to travel.
What do you pack, or not pack? How much should you plan in advance, versus letting spontaneity run its course? Where do you keep your money? What if you don't understand the language?
As a preface, there's no right or wrong way to travel. Below are my suggestions drawn from personal experience.
Some like to plan every detail while buying the plane ticket six months in advance. Others like to hop on a plane and see where that takes them. I'm probably somewhere in between, with an emphasis on the under-planning side.
The one thing that's certain is that you won't be prepared for everything that will come at you. That's OK. You'll get over it. It's more fun if you realize this beforehand, and preferably, have a sense of humor.
Google Flights: A new favorite. Put in your departure date, and it auto-shows you all the prices for the next 2 months for your destination airport.
Kayak: An old favorite. Also great for finding hotels, gaging prices, and price predictions on when to buy.
Google Matrix: A more complicated, but effective tool for finding options across tons of airlines.
Skyscanner: Add your departure location, and click "Everywhere" to scan prices for a spontaneous trip. Only for the adventurous.
StudentUniverse: If you've got a university email, take advantage of the great deals here. Note that frequent flyer miles might not accumulate as typically expected because of the steep discounts.
If you're not strapped for time, I'd also recommend looking into long layovers. I explored Hong Kong and Kuala Lumpur by pushing my flight back a day or two for no extra charge (interestingly, I've taken the flight from KL to Beijing on Malaysian Airlines). Iceland is a popular destination before Europe, and Istanbul Airport offers free "whirlwind" tours if your layover is 6+ hours, free of charge. Considering how much Istanbul's airport sucks, it's nice to escape for as long as you can.
Hostels can be horrible or fabulous, so it's hard to generalize. Basically, it's a cross between a hotel and a home stay. You get a room (can be private single or a dorm with 1-20 other people), a locker (without a lock), a bathroom (private or shared), and a front desk/concierge to help you with quick travel ideas, local sights, and general information about the area.
Some are better than hotels, some are much worse; some are a bargain, and others are a rip-off. Singapore hostels are around $20, while in Cambodia you can find hostels for ~$1/night (I stayed in one for $3). Again, all of this depends on your priorities. I'm a "location" person, so I'm willing to pay a bit more (within reason) to be in the center of town. 1) This typically makes transportation around the city cheaper and more convenient when I'm actually touring, and 2) it's arguably safer most of the time.
Hostelworld, Hostels.com, and Hostelbooker are the top sites for browsing locations (and reading customer reviews!). Hostelworld has a program if you purchase a card for a flat fee, you can get discounts at most of the "Youth International Hostels" (theres TONS of them) for rooms & such. Savings add up rather quickly if you're on the road for a while.
Perhaps the greatest benefit of staying in hostels is that they're a great way to meet other travelers (if that's what you like), while hotels are more for doing your own thing while in a city for a day or two. I even met locals who were sight-seeing in their own country in China.
Hotels are probably the best option if:
A San Francisco company that's taking the world by storm, Airbnb aims to turn empty guest bedrooms into mini-hotel rooms that provide a rather unique guest experience. You and your host coordinate pricing, rate each other in reviews, and approve each others' offers online, and you get to move in for a night or a few months.
I actually lived in multiple Airbnbs for 3 months and can say:
I have heard both rave reviews and horror stories about Couchsurfing, so while I don't feel comfortable commenting on this extensively, I'll link it so you know.
I've never owned a "top-loading" bag, but they're typically praised for equal weight distribution and water-resistance: go with Matt's if you're on an intense hiking trip. Downside: vertically-loading packs make it nearly impossible to just grab something quickly out of your bag.
My blue bag (pictured below) is really convenient for easy access to everything in your bag and, frankly, differentiation among others' packs. There's plenty of great pockets, padlock holes, and and flexibility with this bag that makes it a good option for hostel-hopping.
You'd be surprised how many times you can get away with the same pair of pants when you're abroad. There's a lot of packing advice out there: pack once, remove 1/3 of the bag (repeat 2x). Personally, my Steve Madden boots fared better than the running shoes (see picture above), which I threw out midway through my trip.
More questions? Just email me!