DL is definitely easier to plan and really does not require a lot of planning! Staying off-site at DL is not that big of a deal compared with staying on-site. If you have the money, I'd say stay on-site but if you are budget conscious and you want to put that money to good use for spending money, it doesn't detract much from staying at one of the off-site hotels within walking distance like HoJo's!
On-site they are having the 5 days for the price of 3 promotiont that would be a great savings! I would suggest minimum of 3 days but 4 or 5 days would be great so you can hang out at the pool in the afternoon and have lots of time to really enjoy the parks! If you have longer, San Diego is close and I would suggest checking out either Sea World, the Zoo, or
Legoland! Maybe even a beach day!
For dining, you don't have to make reservations nearly as far out and ours are really just priority seating. I would suggest maybe Aerial's Grotto for the princesses and Goofy's Kitchen is a lot like the character dining at the contemporary (that I am drawing a blank on the name). You might also consider Blue Bayou for ambiance as you are eating in the POC ride! Otherwise, we just eat CS or monorail out to downtown disney and do either ESPN zone, Rainforest, House of Blues, etc. I have never made reservations for these but sometimes will have to wait an hour or so but we use that time to hit the
lego store etc! There are a lot more CS places to eat everywhere at DL than at WDW (IMHO) and some good ones too! Pizza Port by Space Mountain is one of my favorites as is the walk up mexican food place in downtown disney! If you stay off-site there are lots of restaurant options along the route as well such as Mimi's, McDonald's, Quiznos, etc.
You'll probably want to do a bit of research as far as which rides to hit early, which rides have FP's etc but there isn't quite as much planning that needs to go into this. I think Ridemax works well for planning DL once you figure out what you want to ride each day! Also, keep in mind that you will want to park hop pretty much every day at DL and it's super easy to do by just walking across the plaza! I also love how close DT disney is to the parks! Once we know more about the number of days you are spending, if you'll be riding thrill rides, or child swaping, etc, we'd be happy to offer some suggestions on strategies!
Ooops...you must have posted while I was replying!! See you are staying off-site at your brothers. Just remember to budget for parking! Undercover tourist or off the DL website are good places to buy tickets and yes you should buy ahead of time as they are cheaper even directly from Disney! I would consider doing 1 character meal and then saving money by eating breakfast at home or driving through somewhere and bringing your own drinks, snacks, maybe even sandwiches (at least for the kids)!
Alison