Cor blimey! Where to start? - well welcome to FishingMagic first of all and good post!!!
You don't say whether your Exage is a front or rear drag model, but this applies to both -
You decide whether you like to play a fish by backwinding or off the drag. I like to use the drag because they are really great these days so the anti-reverse switch (underneath the reel) is left in the anti-reverse position. If you want to play the fish by backwinding then put this switch to the reverse, but be careful not to let go of the handle whilst playing a fish as you will just end up in a tangle.
Now the drag. You set this at a point where, when you pull on the line from the front of the reel, it allows the spool to turn with just enough tension to stop your line from breaking. It's a bit of guesswork really, but experience will tell you when you get it right.
When fighting a fish, it will then give line at a point before the line breaks, but if you want the fish to have more line, you can slacken off the drag slightly during the fight. When you want to reel in again, tighten the drag a little until the fish can no longer take line from the revolving spool.
You have to be careful with either method, backwinding or drag, of playing a fish not to put too much force on it. When the fish wants to run, let it and when you feel you can take up any slack line, wind it in. It's all down to experience and playing about with it.
Now the EXAGE in particular- IF it's the reap drag model. You have next to it a "fishting drag", a little lever that flips from one side to the other. Twist it to the left and it slackens off the drag, to the right tightens up the drag. This is much easier to use during the fight because you know in which position it will give more line or not.
To set it up, push it to the upright position and then set the drag behind as you did above so that the reel pays out line before the line breaks. When fishing, push the lever over to the left a little and it will pay line off a little easier, but when you need to restrain the fish, push the lever over to the right.
Hope that all makes sense, but ask any further questions if you like.
