Let's see.... do a search for Ryanair or FR on this forum and you'll see the pitfalls to avoid. Don't assume any rules will be bent for you.

- print your boarding pass at home, pay for bags ahead of time if you're planning to check.
- make sure your carry-ons and kids don't exceed allowed size
- ensure that you're at the gate waaaay before it closes
- if you're non-EEA/EU get your documents checked at the desk. Not sure if you need to do that anyway since you have kids.

Not sure that there is anything else that needs to be considered.