I've had the pleasure of traveling to several countries around the world and here are a few tips off the top of my mind:

For domestic flights, I suggest arriving an hour and a half before your departure time. For international flights, I suggest 2 and a half hours. There have been times when I've checked in, passed through security, and made it to my gate in well under an hour for an international flight, however, sometimes I've arrived to a huge line of people all waiting to check in on the same flight abroad and the process took a couple hours. It all depends on the time of year and such. Better safe than sorry!

I'm not too picky with clothes. But my primary advice is to dress comfortably! Air planes can be very squishy and depending on your flight path you may want to take a nap!

Since you have plans stretching out to the end of the year and this may be a regular thing for you... please please please sign up for frequent flier miles! All major airlines have it and the points you will accumulate will potentially save you a lot of money down the road!

I've used many sites such as travelocity, orbitz, cheaptickets, ect... the best one in my opinion is kayak! Its pretty much a consolidated search engine that seeks out and compares information from all the major sites. They don't sell anything, instead, point you in the right direction for the best prices.

That's all I can think of right now! (I've purposely omitted some other international tid bits, but I don't think you have abroad plans yet!)