It's very much an individual thing - I know there's been some heated debates on here about it but you're obviously interested in gathering more info or you wouldn't be sat on these forums gobbling up as much detail as possible :)
I'm not the organised type, I usually like to lay horizontal in the sun for a couple of weeks but when we book Orlando some dark, demon planner emerges from somewhere. I know exactly where it's come from - my earlier mistakes. This is our 4th time to Orlando in 10 years. The first time we went - we wandered around aimlessly for most of the two weeks, overwhelmed by the crowds, the queues and the sheer scale of things. I swore I wouldn't go back as it was so stressful however I knew how good it could be and then someone introduced me to the Unofficial Guide so I went back armed with a touring plan. It was the most inflexible plan you can imagine - not accounted for toilet breaks, food, basic human behaviour and I turned into a sergeant major, barking orders at everyone and having palpitations should there be any deviation to the touring plan.... This was equally as bad but the next time I managed to get that balance and found out that the more planning I did, the more I learned and the more flexible I could be cos I had a touring plan worked out for just about every eventuality :)). Bingo!!! I know it's not for everyone but now I actually enjoy the planning process and am much more relaxed (albeit still as busy) when we're away :). So although I may come across as completely anal - it's just my split Orlando personality lol.
There are some fantastic people on this forum who offer some amazing tips and advice you won't find anywhere else but if you do want to plan more - here aremy tips. I thoroughly recommend the Unofficial Guide to Walt Disney World - especially for first timers as it gives you some really good advice on all the individual attractions and rides, especially useful if you've got any nervous kids so you can make an educated decision on what is more likely to frighten them. It also introduces you to the idea of a Touring Plan (you don't have to use one but again it's a good idea to understand why you might want one).
Then if you're not staying on Disney, go onto the Disney website and look at the calendar for the dates you're there. Make a note of each day and the parks that have extra magic hours (you want to avoid these as they're supposed to be the busiest days).
If you want even more detail - www.touring plans.com (spin off from the book) offer a pretty scientific crowd calendar that tells you out of 10 how busy each park, each day is - plus the recommended park and the park to avoid for any given date. You can also personalise your own touring plans and there's a cool iPhone app that gives you wait times - real time. There is a subscription charge for this but if you want me to just have a quick look at your dates, I don't mind.
Orlando Informer also offers a crowd calendar which is free for Universal and IOA and I believe Undercover Tourist do too.
There are lots of other forums out there too - but you'll lose the rest of your life to them...
I created a spreadsheet and overlaid this info so I could choose what days to do what parks and then make any restaurant reservations based on it.
Hope this helps the anal amongst us - for the rest of you that don't feel the need, I'm very, very jealous :)