Just got back from a week long stay in Florida a few days ago. I was there for the shuttle launch which ended up being scrubbed but we planned a wdw vacation at the same time so it definitely came in handy. I stayed off site about five minutes away to save money but staying on their resorts would have definitely been nice as well.
Parking is about $15 a day at each park so take that into consideration if you'll be driving.
I would go here for all of the tips you may possibly need...
www.mousesavers.comThey have a newsletter they send out the 15th of each month with a slight discount to tickets. That's where I bought mine from. There are very few coupons or discounts out there though. AAA may have some if you book a full resort package but as far as tickets go, that's the best option (or a scalper/craigslist/etc if you want to risk it).
The Unofficial Guide WDW book has a checklist and order on how you should visit each park (based on if you'll be there 1 or 2 days at each one) and it was a flawless system. We were able to ride all of the rides, see the shows, take our time, etc and we avoided the masses. If you are not going to have access to the extended hours (staying off site) then avoid those parks for that particular day so you won't have to deal with the crowds.
Also visited both Universal parks and there is definitely a huge difference how Disney caters to its crowd vs. how how they do it. Universal had some great rides but didn't have the "magic" that Disney seems to have.
If you want to save some money I would suggest having a small backpack or daypack and filling it with snacks. You can take water bottles too (I even brought in Starbucks a few times so they're definitely lenient with what you can bring in) but since that get heavy you can usually just ask for a cup of ice and water at almost any place and that will help some. Only one place at Hollywood Studios happened to have a self-serve soda fountain but any of the drink places are more than happy to give you water/ice.
Like others have said, don't rush through and try to do everything at once.