As far as simple maintenance and cleanin goes, making sure to dry fire your gun once or twice without a mag after every game to make sure the champer is clear and the spring is uncompressed is one thing to do.
For keeping your barrel clean, you can use the supplied cleaning rod if available, and using some fine cloth to groom out the inner barrel to insure that it is dirt free. Be sure to dial your hopup all the way down so you do not accidentally tear the hopup rubber.
If you have been playing in the rain, make sure to wipe down your AEG, and if you are up to it, even take it apart strip and wipe out the mechbox and regrease it as well if you think moisture has gotten inside.
From a safe handling stand point its best to store your AEG without the battery in it. If you have a PTW its especially important that you do not store your gun with a battery in it as it will damage the battery, however this is not the case.
As far as cleaning goes there is only so much you can do, on the note of maintence its good to pop your mechbox once or twice a year just to make sure that everything is lubricated properly, however how often you do it is in direct correlation to how much you fire.
"Its only a little bit on fire"