Lots of great info here of course. Just start asking questions and most likely someone here will have some info. I know what you mean about being a visual person & sometimes I like to see/hold a book too, as well as online stuff. I have a Universal Orlando book/guide by Kelly Monaghan & it's been a good general reference. (It even gives kudos to the DISboards "DIS" and encourages readers to check-it-out) 
Islands of Adventure is made up of themed lands. There are also areas at the Studios but not as defined as Disney...remember...Universal is a working studio so it's not really divided like a theme park.
1-Whichever one you want! If you plan on spending one day per park, it won't matter. They're both fun.
Universal is awesome and you will enjoy (there's a reason I've gone here twice in a row. Though the Mouse is calling me back this year)! Its so much more laid back than Disney, you don't even need to make reservations to eat anywhere! Though, you can if you're incredibly OCD (like me, but I only make ressies for the Emeril's restaurants...of which I've only eaten at Tchoup Chop so far, but I digress). Universal's website used to have a interactive map for both parks on it, maybe it still does.
Go to this page ---> http://www.universalorlando.com/Theme_Parks/Universal_Studios_Orlando/universal_studios_florida.aspx ... and on the right hand side you'll see a link "Universal Studios Florida Park Map" ... it's an interactive map where you can click on each attraction/restaurant, etc, and get more information.
