Five days should be a good amount of time to see and do DLR. And, welcome to MP! May I suggest that you read and familiarize yourself with the FastPass system. There are good articles here at Mouse Planet. Also the FP "trick" is that they don't "expire" at the end of your window, but are good for the remainder of the day. You can collect FP's during the day and have easy entry to a whole bunch of "e-ticket" rides in the evening.
I usually combine my days with rides, shows and attractions. Our rest time is usually at meals. I always leave the day "flexible" to catch something I didn't expect. This has included a Disneyland Band concert on Main Street, with guest conductor Eeyore, the firehouse band, Mary Poppins and Bert with the Button Band, the show outside of the Golden Horseshoe, a lariat twirlling cowboy in Frontierland, a jazz combo in New Orleans Square, PUSH, the talking trash can and the trash can band in Tomorrowland.
Make some Priority Seating reservations for restaurants such as the Blue Bayou, Carnation Cafe, Cafe Orleans, and many in DTD. We've had a late lunch at the Carnation Cafe, for instance, and stayed there to watch the parade.
There is so much to see and do, you need to have a plan, but also be FLEXIBLE. Lastly, I would pre-plan the first four days, then let Day #5 be a day to re-experience your "favorites". It will be sad to leave, but you'll go out with a bang!
Hope this helps!