Hi-
I've only been to DLP once myself, this past August (beginning of the month), with my DH. I hope to finish my trip report soon, but I'll answer some questions to my best ability.
For planning, we really did none, other than deciding which day to go, how to get there, and finding out the hours the park would be open. We were fine, as if you know something about WDW's Magic Kingdom, that's a pretty good preparation.
However,
www.disneylandparis.com is a pretty decent site (the official one).
We've never been to the DLP Studios, but the
Disneyland Park can be done in one day. If you want to ride everything 4 times
, you may need a second day, but a full day visit should be fine. You can buy tickets either at the park, at most Paris hotels, or at the
Disney Store on the Champs-Elysees. The price is the same at each of these. I'd skip out on the tour group trips to the park, as they jack up the price tremendously and give you fewer hours in the park. The RER (metro Paris subway) is pretty cheap, and really easy. The Disneyland stop (Marne-La Valley Chassee-pardon my spelling) is the last on the line, and is literally a few feet from the Disneyland entrance.
When we went, I think the park hours were 9 AM-11PM, which including an evening parade (Spectromagic-like) and fireworks. Unlike WDW's MK, where everyone seems to be rarin' to go by 8:55, DLP didn't pick up until around 10, so the park looked empty for that first hour. Later in the day, the crowds grew, but they were never unbearable. Some of the big-ticket rides (Thunder Mountain comes to mind) had 40 minute waits (appx), but DLP does have FastPass, and other rides had more reasonable waits.
One thing to keep in mind about an August visit, although it may not bother you: when we went, France was in a big heatwave. In many places in the US, when it gets super-hot, the AC is blasted and ice-cold drinks are served. The French don't do this. AC is hard to find, and is usually pretty mild, and cold water can be impossible to find.
I'm thinking off the top of my head, so I may forget some, but these were among our favorite attractions. I'll put full details on everything in my trip report.
Favorite rides:
Space Mountain (different from WDW's, is much wilder, goes upside down a few times)
Small World (they have a full room for the USA and Canada!)
Indiana Jones (backwards roller-coaster)
Thunder Mountain (similar to WDW's, but lots of fun)
Phantom Manor (Haunted Mansion. No dialogue, though)
Pirates of the Caribbean (same concept, but different from WDW's)
Many of the Fantasyland attractions were cute (some just like WDW, such as Mad-Hatter's Tea Cups, some unique, like the Casey Jr. roller coaster- about the "fear" level as Goofy's Barnstormer)
Go inside the castle. There's a Dragon in the basement.
The Disneyland Railroad was cute. A lot like the MK's, but no narration. Handy for getting around, though.
Rides that are like WDW's:
Star Tours is exactly the same as MGM's, only it's presented in French. Still fun, though.
Honey, I Shrunk the Audience is the same as Epcot's. It's presented in French, but there are headphones available for other languages.
Autopia: like MK's
Different name, but there's something like MK's AstroOrbiters. I loved this one!
Other:
I don't remember the name, but there's a 20,000 Leagues under the Sea attraction that's a walk-through of Captain Nemo's submarine. Cute, but not that worth it, IMHO
There's a Timekeeper-equivalent. We didn't do it, though, as we never cared for the MK's Timekeeper
Many of the shops are cute. In Main Street, USA, there is an Emporium, just like the one in the MK. My DH spent a long time waiting for me outside this shop.
The daytime parade was (and still is) the Princess Parade. Very cute. If you enjoy WDW's daytime parades, you'll like DLP's. I still remember the song distinctly, nearly 6 months later. A little advance spot-holding required, but not too much.
The nighttime parade was great! I've always loved Spectromagic, so I wasn't surprised how much I loved DLP's. A must-see if you like the night parades. We had to hold a space to sit for a while.
We had lunch at the Blue Lagoon restaurant, which we really enjoyed. It's in Adventureland, and it overlooks Pirates of the Caribbean. We came around 11, made a reservation for around 12 (I think), and did some rides in the meantime.
We had dinner at Auberge de Cendrillon in Fantasyland. A great place to have classic French food! We went in about mid-day and made a reservation, although the place was not crowded when we went for dinner (not empty, but definitely not bustling).
Oh, English menus are available at all restaurants.
Hope this helps at least a bit!
but feel free to PM me with any other questions. We're in similar situations- young American couples going on a day trip while visiting Europe. 
