The very, very first thing you should do upon getting into the game is to check and change your controls. The way it is set up isnt exactly intuitive, so be sure to check and customize everything before you get into the game. Using controllers will make things easier to control, but may slow down your ability to react.

Once you get your controls figured out, you should be able to get right into the game. For gamers that are used to playing newer games that baby you, this may be a bit of information overload. Don't take that as an insult, it isn't, and don't get frustrated. The game will try to ease you into how things work by starting you off in a PT boat in Pearl Harbor. Yea. That's your easy intro mission. Pearl, on Dec 7th, and you're in a PT boat. A little information overload is nothing to be ashamed of once the bombs start dropping. You will have to drive the boat while also firing at enemy aircraft and not watching where you are driving. So take things slow and try to ajust to the controls. Be sure to select the group of planes you are shooting at as your target, it will make downing them easier. The encounter will last just long enough for you to get a feel for what you are doing in the PT boat before giving you new objectives.

Later in the mission, you will switch from being the entire crew of a PT boat to being a pilot directly attacking enemy fighters and bombers who are attempting to land on their aircraft carriers. Tail gunners hurt, as does anti-aircraft fire. Try to attack from an angle behind and above, and be sure to select who you are shooting at as your target. It will give you a little circle out in front of them to shoot at, making leading your targets much easier.

In later missions, you will have to use a wider and wider array of units, each may have a wide array of weapons.

Line of Sight:
Line of Sight is a real issue. Guns in the back of your ships can't shoot through structures in front to hit enemy targets for, well, obvious reasons. You will generally have to get sideways when attacking targets to ensure

Artillery/Anti-air:
Many ships use the same exact guns for both surface-to-air and surface-to-surface combat. Be sure to keep this in mind when it comes to your smaller ships.

Artillery physics:
It takes time for your shots to land after being fired. The longer the distance, the more time it takes. The game does not compensate for this on its own, so you have to. Try aiming for the front of enemy ships in order to hit them mid-ship. depending on speed, this can damage their engine or blow their magazine, allowing for easy kills.

Torpedo:
These are just as dangerous to your own fleet as they are to the enemy if used improperly. Be sure to only use them at either stupidly close range, or if there is no chance of your own ships getting in their way - which isn't as simple as it sounds.

Your ships don't respawn and neither do your aircraft. So use everything wisely.

Fighters can be used as bombers, if you arm them with bombs. They move faster and are still more able to dodge than bombers are, but they do take a hit to their mobility just from carrying the extra weight. Bombers are also able to be used as fighters as long as you enable Combat Air Patrol (CAP) for them. They can do a pretty decent job of tearing up enemy bomber groups by attacking them, and also using their tail gunners to damage any aircraft they aren't chasing. This is especially useful knowledge in the later levels.

Try to preserve your ships as much as you can. You might think you can use smaller ships as fodder later in the game, but are still more useful than most people give them credit. Their anti aircraft abilities can help protect your fleet, most smaller ships also have Sonar that can detect Subs, as well as depth chargest to destroy them. Remember, you do have a Damage Control screen. Be sure to use it well. Mostly water damage will be your main concern, but if you let a fire get out of control, or let your engine take too much damage, that will also make a mess of things.

Your AI may seem like they are dumber than a box of rocks, but they will do whatever you tell them, and often do it better than you can. Your AI will generally be more accurate when attacking enemy ships at range than you, and their formations in the sky can better ensure victory than you taking control and running in a straight line at the target. Be sure to use your tactical map often and issue orders to all of your units, even the ones you are personally controlling, to ensure you are making the most of all of your resources. Anything that relies on Torpedos, though? Like Subs? Yea, never tell them to attack anything themselves, they will end up out of ammo and dead quickly, with the exception of torpedo bombers, they do great.

I hope this helps.