I would actually not recommend the hotels on-site. I went back in August and we stayed at the Tropicana Inn, which is literally across the street from the park. You can leave your room and be at the gates in five minutes. My aunt and cousins went in November and stayed at the Disneyland Hotel and said not only was it a farther walk to the park, but that it wasn't really worth the extra money since most of the time you're at the park anyway.
Hmm, what are good tips...It was extremely hot and humid in August, more humid than I'm used to in Southern California, so make sure to stay well-hydrated and well-sun screened. I got horribly sun burnt my first day there and it really put a damper on the rest of my trip.
I would recommend doing the big rides first thing in the morning when the park is still a little empty. POTC, Haunted Mansion, Peter Pan, BTMRR, Splash Mountain, Indy, all of these will be packed during the day, so make sure to go in the morning or late at night.
According to their site, the fireworks show, Remember...Dreams come True, will be there this summer too. I highly recommend you see it three times if possible. Try to see it in front of the castle, right in front of the Main Street train station is perfect for a full view. Another night, go behind the castle and watch it from that angle, it's cool too. And my personal favorite and well-kept secret: go to Small World and watch it there. You get a 360 degree view of the show and images projected on the side of the ride, and not many people go there, so the view is great!
Make sure you plan enough days there to really savor the trip. We stayed for five, and it was a little too much. Four days is perfect to see both parks and do all there is to do to your heart's content. Make sure to take the time to see the little things, like the shopping and the architecture and details that you don't normally look for. It really takes a trip to D-Land to a whole new level.
Well, I hope some of this helps, let me know if you need anything else! Oh, and have a great time! D-Land is the best!