Depending on what type of person and packer you are, AND where you're going - you may decide to pack differently. I, however, have experience moving abroad for months at a time and widdling down my wardrobe to the essentials for stints of life on the road. I have found that I prefer backpacker style bags to suitcases, just because I spend a lot of time backpacking when I travel. If you are in one place the entire time, a suitcase might be best suit for your international adventure.
A few essentials: laptop, camera, toiletries/hygiene products, a carry-on duffle bag, and your purse/personal item. Packing can be very daunting, and it can be really difficult to really narrow down what you bring with you and what you'll actually need or use. If there's something you forget, chances are you can find it abroad. If you bring too much crap, chances are you're going to regret lugging it around with you - but then again, sometimes it's better safe than sorry! I'm a light traveler, and a minimalist - so if you're someone who has a hard time being decisive this can help. If you'd rather overpack than underpack, you might want to ask someone else :)
Must have: enough t-shirts, blouses, and tops for a week. A pair of good blue jeans, colored, and print - as well as a few pairs of shorts and skirts. Maxi skirts are great because they're comfortable and go with everything and are versatile for traveling. I always bring my favorite hat with me, but end up bringing 5 because I wear a lot of hats! Sunglasses are necessary, and be sure to remember a light and thicker jacket for weather. If you're going somewhere warm, you can decide otherwise - if you're going somewhere cooler or where the seasons vary, bring something for each.
Packing tip: roll your clothes, don't fold them! Creates a lot more space.
I have lived in China with 4 t-shirts, 1 pair of shorts and 1 pair of pants on my back and that was it. Oh, and a change of undies for 5 days. I had to do more laundry but I had very little to pack. I ended up buying clothes and items in China and bringing them home with me, with room to spare. I did the same thing when I lived in Peru and Ecuador, because I always, always, ALWAYS end up shopping in country and having fun loading up on local goodies. I'd rather have room to bring stuff home then have to buy a bunch more luggage to haul it all back - but that's just me :)
Good luck with your packing! Leave a comment below if you have any specific questions, and we'd love to help you. Don't dread it too much - once it's done, it's done! Ya just gotta get the motivation to dig in and get started.