Hey Katherine!
There are a couple of different ways to see the different crowd levels and seasonal pricing information for Walt Disney World.
If you're most interested in how crowds will be at the parks, your best bet is to visit an unofficial site like TouringPlans.com. They give a breakdown of how crowded they predict the parks to be on any given day. We use them for planning our vacations and have found them to be quite accurate.
If you want to know what Disney considers Peak, Value, or Holiday season as far as room pricing goes, you will want to check out the pricing grids for each resort. For example, if you're looking at how room prices vary for
Disney's Pop Century Resort, click the link to be taken over to the
Pop Century Rates page. You can then use the drop down menu and select different seasons to see how room rates fluctuate.
I hope this helps! Please let me know if there's anything else I can help you with.
Have a magical day,
Ashley