Well, I went in winter- a few years back, and half the attractions were closed, but it was still pretty fun.
There's going to be a HUGE cue though. Major.
I went in the middle of bloody winter, and it was all of 2C when we went and the cue's were still enormous. I waited an hour to get onto this star trek enterprise ride.
Make sure you go on the Jules Verne Roller coaster thing.
It's the one in the middle of Disneyland that has the rollercoaster going through this like... Gun barrell thing on the side of a massive roundish building. It goes up through that gun barrell thing, and into this dark thing.. it does corkscrew 360 degree turns, and it's pitch black, but there are flashes of ligth and stuff.
Make sure you keep your head back against the head rest thing, (If you can) cause it hurts. xD It really really hurts.
It's quite cute.... but a little boring once you've done a few average rides.
The usual stuff like 'it's a small world after all' and things are there. The teacups are there, flying dumbos (like at wonderland) but nothing to great. xD
It is over priced and I warn you. I warn you deeply.
DO NOT GO TO THE BLACK LAGOON cafe.
It's bloody awfull. (Overpriced too).
There's the shops and all, which are pricey- but cute, and traditional "USA DISNEYLAND" style but yeah.
You can watch the parade at like 6pm or something, down 'Main street USA' xD So corny. You can catch the old train that goes around Disneyland, and you can visit the Fantasy Castle (you know, the big pink castle where sleeping beauty and all that is).
If you're a thrill ride person, there's probably 3 rides that are worth going on, apart from that- you need to be a little tot to really go crazy in disney land ^^
Oh. Catch the train early in the morning, if you're leaving from the centre (city) of Paris. You have to take two trains, and it takes a while!
They have english guide maps too for Disneyland, so be sure to pick one up outside the gates of disneyland, because you'll have to speak french otherwise. xD