Hi, Amy! Don't feel any pressure to schedule a character meal! My brother and his family have only ever done a character meal when we took them once to Chef Mickey's, and he still talks about how they would have rather stayed in the park on the rides!
If you decide you would like to do a character meal while on your vacation at Walt Disney World, you just need to call 1-407-WDW-DINE. There are character meals all over Walt Disney World, in both the theme parks and the resort hotels, so you will have to decide which meals you want to go to or which characters you would like to see. The character meals book very quickly during peak times - especially Cinderella's Royal Table and Chef Mickey's - so you may want to call right at your 90 day window to book the more popular meals.
To get an overview of the character meals that are available, I recommend visiting
www.allearsnet.com . If you click the dining tab, you'll see on the left side of the page a link to tell you where the character meals are.
I try to book meals at the parks we'll be visiting, which lessens the chance we'll miss our reservation! That may help you as well!