A few tips for those of you just getting started.
First off, I highly recomend starting with the D7, its pretty much the spit 16 equivalent.
2 guns, 500 rounds per gun lets you rack up several kills.
But before you dive in there, I'd suggest a couple of settings changes.
Esc, options, preferences, flight.
Combat Trim seems to do some funky things to planes without trim.
I know I had no luck landing one with it on, and had no problems once it was turned off.
Also the govenor setting is found here. I'd suggest turning it off.
Then watch your throttle in a dive. If you start creeping into the red back off the throttle.
You can get more speed out of your plane with it set to off. But you can also break your engine in a dive.
So you decide, but I'd suggest trying it both ways.

Just as an idea of what your looking for in a sight picture.

Get in close, put rounds in the cockpit, fuel tank, engine.
Only takes a few rounds to wound or kill the pilot. Fuel leaks run you out of fuel very quickly.
Watch out for collisions!
Combat is close and wild, not so much a knife fight in a phone booth as a switchblade battle in a suitcase.
Don't be afraid to dive in!
Last, please, leave your ego at the door, along with frustration, anger, and normal trash talk.
Friendly banter is one thing, but the second it goes beyond that its an immersion killer for the rest of us.
The WWI arena's are off to a good start but please do your part.