Everybody's gotta start somewhere.

This is my first time planning as well. So far, my main sources of information have been Mousesavers, these forums, the Unofficial Guide, and Tour Guide Mike. It's a complete overload of information. What I can tell you is that what I started with was a blank spreadsheet. As I began reading and learning things, I put them into the spreadsheet. I'd have a tab for hotel/resort info, one for tickets, one for dining, one with a general agenda, and even one just for random tips I would read. I saved links to even more info, etc. etc. Gradually over the last few months I've fine tuned it and organized it even more. It's still a bit random, but I pretty much have all the info I need to pull off this vacation.
The key is to keep in mind that you CAN over-plan things. There's a big difference between being informed and being overinformed.

You don't have to be a Disneyophile, you just want to pick up enough knowledge to make more right decisions than wrong ones. Keep gathering information in whatever format works for you, then take time to sit down and digest the info - discarding what you don't need. I have our flight, our condo, our rental car, our tickets, our ADRs, and what parks we'll be going to on which days planned already, and I feel pretty good about it. Some people would still be freaking out about what exactly they will be doing at the parks etc. etc. To each their own.

I have two kids that will undoubtedly alter and minute-by-minute plans I could possibly conceive, so it doesn't make sense for me to worry that much about it.