Welcome, Kristen!
My advice....read, read, read. Try the stickies at the top of each category (tickets, resorts, fast pass, characters, dining, transportation, etc.).
Get yourself acclimated to the abbreviations used and board policies about what you can post, etc. and then JUMP RIGHT IN to the questions and discussions.
We took our daughter when she was 4 going on 5 to her first trip to WDW and -- wow, what a great age to go. She is 9 now and remembers that trip so vividly and talks about it often. "Remember when I was just a bit scared to go on BTMRR (big thunder mountain railroad) and decided to be brave and try it? And then I just giggled and screamed the whole way and when we got back into the station I yelled AGAIN! and everyone laughed? And then I rode it 4 times in a row? Now I put my arms up on that first hill and it's my favorite ride!"
You don't have to post a lot to GET a lot out of the forums...heck I've been around for 6+ years and my post count is low compared to the majority of folks.
Good luck planning for your magical trip with your family!