Holy smokes does it get packed now. Someone has a website for it with tons of info that posts on here I hope they check in. I can't find it right now- Kind of an Unofficial Hershey site. It was great.
The park is great fun but don't forget about those hills. People walk to get in shape for Disney- but Hershey to me is where you need to train.
They have opened and this year expanded their "water park" area.
We have never done that as it was PACKED the day we were there. But it looked like great fun and maybe now that it's not brand new it won't be so bad.
Do you have kids? how old? that would help. One thing I love about Hershey is that they have Kiddie rides spread throughout the park. So if you have roller coaster riders you won't just be sitting waiting for everyone else- you can take younger ones on the little rides right next to the coasters.
Some Great roller Coasters! Fun. The Reeses ride to me is a bust- it's no Buzz Lightyear ride. And it breaks down often. If there is a long line I would skip it.
Another GREAT cheap park is Knoebels
http://www.knoebels.com/
Probably about 90 minutes from Hershey? Maybe less.
It's free admission and sometimes has POP days- other than that it's pay as you go.
The food is great there. Always gets voted top amusement park food.
Places to stay? Well we've stayed at the Clarion? I think? There are tons of "chain" type hotels nearby. Suites hotels ect.
We have stayed at both the Hershey lodge and Hotel Hershey. To me the Hotel Hershey wasn't worth the money. We kept looking at each other saying do these people realize we're in Pennsylvania not manhattan?
The lodge was just motel like in the dark rooms but they do have free mini golf and a great pool- indoor and outdoor. My kids really enjoyed this one. It was convenient. But honestly the other hotels are maybe 2 minutes further.
So it's really up to what you want. I know there is a small mom and pop place that people like.
If your kids are younger there is Dutch Wonderland- but that's for the under 10 crowd I would say.
There is also Strasburg Railway-
http://www.strasburgrailroad.com/
Thomas weeks are fun but so are the normal weeks if you are a train person.
Where are you coming from? I could come up with a bunch more if I knew your travel route.
Oh and we went at Christmas- It's really just the kiddie rides up front and a handful of others open. They don't have the College staff to keep more than that open at the Holidays.
The only issue was a LOT of the rides were closed. 
We had a good time and everything but not enough was open for me to really give you the low down on all that it has to offer.
I think they were more surprised than anything. They laughed and talked about it being fun, but declined doing it again! 
to eat. Waterpark was closed when we went- too cold- but we want to go back for that. There are quite a few roller coasters, so if you are a coaster fan, you will get your fix. I have also been to Dollywood- also a beautiful park. Lots of fun there too.
