If you decide to stay off site, I have the name of a company that manages rentals. It's not a timeshare company, they manage condos for owners who don't live locally. We always stayed in the same unit. It was a 2 br/ba condo. It was really nice and quiet. It's a 10 minute drive away, tops. Top notch service.
Rooms at WDW are costly for what you get. We've only stayed on-site since they've gotten aggressive with the discounts. I thought the discounts brought the rates close to the market rate. Although we love staying at the Beach Club Villas (Condo/timeshare accomodations), for more money, we had less space than we had off-site. For instance, we had a one br/ba villa versus 2 br/ba offsite. Also, the condo we always stayed at off-site seemed to feel more like home than the Disney one. But we were right in the middle of the action, so there's a trade-off. I love staying in condos. I'm a vegetarian and I have no problem rustling up a few meals throughout the week, but I recognize others might not want to do that.
There are pros and cons. I saw some really reasonable prices to stay at Reunion (fancy new golf resort community), but my husband likes staying onsite now. He likes to come back for lunch and have a beer or two. He couldn't do that off-site.
Just to overload you even more, there are 4 tiers of accomodation at WDW: value, moderate, deluxe, and villas. Then there are different "seasons" for room rates.
And I also recommend the book DixieGirl mentioned. It's pretty unbiased, IMO.
Sorry, I couldn't resist adding to this thread.