We did exactly what you are doing 2 yrs ago. It was my DH and DD's, then 6 yrs old, first Disney trip. We kicked off our trip with a dinner at Chef Mickey's. We loved it. It was a great way to get in the Disney spirit. My DD wanted to fill her autograph book and with so many characters at Chef Mickey's, she was off to a great start. Chef Mickey's has all the classic Disney characters, so it just seemed like a great welcoming. The atmosphere was lots of fun. The characters were very interactive. The food was fine. I can't really remember any of it, but I also don't remember anything awful about it. It's typically buffet stuff.
We are going back to Disney this Fall. Chef Mickey's is on my DD's must do again list.