We just got back from 4 nights/5 days at DLP with our two kids (6 & 9) and my parents. We travelled with Eurostar and stayed at the Hotel New York, which is one of the Disney hotels, so we got early access to the park from 8.30am. Not all the rides are open early, (the really popular ones open at 10am, when the main gates open), but if you're organised you can hit some of the smaller rides and be first in the queue to get a fast pass for the busier ones. Saturday (the first day of half-term), was really busy, but Sunday was much quieter (it was a religious holiday in France, so maybe that had an impact?). Weds was fab - small-ish queues for everything.
With five days you can take your time and we managed a day in Paris as well (the train station is next to the park entrance and it's 40 mins into the centre of Paris). If you have less time I would recommend two full days in the parks, as there are two of them - Disneyland and Walt Disney Studios (which is like Hollywood Studios in Orlando, but a bit smaller).
I would also recommend getting au fait with the fast pass system before you arrive. If you've been to Orlando and used it there, it's not quite the same! At DLP you cannot book your fast passes online or in advance. You have to turn up at the ride itself and get the fast passes from the adjacent machines. The machines open at 10am and once you've got your passes you'll see printed on them the time at which you can book your next lot of fast passes, but you'll have to traipse across the park to find that ride in order to get them. Plus, not all popular rides are on the FP system, so for Autopia, Crush's Coaster and others you simply have to queue up.
Food inside the park is not that great and it's expensive, but you can take in snacks or a picnic. I don't think you're supposed to, but no-one stopped us taking food and drinks in our backpacks. Outside the park in Disney Village and my top tips for restaurants would be King Ludwig's Castle (which has good beer and surprisingly nice food), and if you're gluten-free then Planet Hollywood has a full 3 pages of their menu full with GF items inc. pasta and pizza and all kinds of stuff we don't usually get offered!
The buffet breakfast at the Hotel New York was very good (we had vouchers as part of our deal), the pool there is large and pleasantly warm (but deep - I couldn't touch the floor and I'm 5'4"), and there is a very nice walk around the lake outside.
All in all it was a great trip with rides to suit all ages and temperaments!