I gotchu, gurl. The main difference in AP shaco and AD shaco are the playstyles. With AD you're typically going to just play like a normal assassin, go in, attempt to get a kill, attempt to get out. AP Shaco doesn't have nearly as much burst, but what he does have is much stronger poke (1:1 ratio on E) and way lower cooldowns (Q cooldown goes from 11 to 6, W goes down to 10 with 40% cdr, which I get easily with runes and morellonomicon) which makes for easier escapes, safer split pushing, and way more traps and zone control. I play AP shaco like a zone control mage. Early on (I typically play him top lane) you wanna set up your boxes like heimerdinger turrets, in a triangle. The reason he's so good top lane is because he thrives on enemy aggression. Slap them with E until they get so annoyed with you that they engage, lead them to your boxes, enjoy the free kill. The triangle formation will not only ensure that they won't one shot all of your boxes, but also let's you maximize your CC. What it comes down to is if they continue in on you after triggering the first box, they'll trigger the second, now they're fighting in two boxes that each fear for a second and do about 500 damage if left alone. If they continue to go, they trigger the third and will die pretty much no matter what. Now I know what you're thinking, that's a great way to cheese, but I doubt it'll work more than once against an intelligent enemy. You're right, against good enemies you'll probably get one kill on the top laner and two on the jungler doing that before they wise up, but the good news about that is it doesn't have to get you kills. Proper box set up and use of Q will make you damn near unkillable in lane, but safety aside, if the enemy top laner refuses to go in on you and the jungler can't gank, you're free to either roam and let your boxes minion farm for you, or poke the hell out of the enemy top laner forcing them to back and miss farm. I like to force a back out of the enemy top laner, push his lane, go into enemy jungler and kill the jungler before the top laner gets back. Anyways, enough about lane, more about late game.
Late game you've got your initial job of killing the enemy carry, but you've also got more to do. With your boxes doing around 500 for three attacks (three attacks is what you're assured if an enemy walks into a box alone, unless they walk back into it after the fear, the fear will actually make them run out of the box's attack range) they ain't nothing to fuck with. With full cdr, you've got them on a 10 second cd, they last for 60, that means you can have 6 out at a time. You can either stack 'em up and hope someone runs into them for a sure kill if they don't have Bveil, or you can spread them out for some massive zone control. Use them to keep enemies off baron and dragon, stick them on the sides of mid lane to prevent enemies from flanking you, stick them where you think a teamfight will break out and enjoy a shit ton of cc and damage the next teamfight, or use them to warn you of gankers when you're trying to split push. There are so many uses for these little buggers. It's all about preparation. You choose where your team fights. You need to control the enemy team's actions. Moving on, your ult should be on a 48 second cooldown, 30 if you get the full duration of the clone, so don't be afraid to use it for silly things like poking the enemy team under tower, baiting them into box nests, clearing waves, or just fucking with them by randomly sending it into the jungle for the enemy jungler to kill and do 1k damage to himself on. Also I should mention how much easier it is to survive teamfights with AP shaco. Not only are people more afraid of your clone, your Q is on a 6.6 second cd. After you engage with it you need only survive for 6 seconds. That's not always easy, but with your ult, your boxes, and your zhonyas, you should be alright.
I missed one of the key advantages to top lane shaco, free level two off of gromp or kruggs or wolves or whatever. Set up your box nest at whatever one is closest to your lane, enjoy free level 2 and gold advantage without missing a single cs or using TP. That being said, you should still take TP as his bot lane TP ganks are extremely potent. Ooo another tip! You can ult, then TP and the ult will appear at the same time as you so the enemy will have no way of telling which is which. You can even quickly use Q to disappear as soon as you get in there and they'll almost always attack the clone thinking it's you.
Hope that helped! It works in the jungle too, but again, sheen items don't work on Q and it just doesn't seem as good as top lane.