When your children are small and people tell you the time will fly by, believe them. Even on those days when the house is a wreck, the kids are running wild and you would kill for a coffee break, believe them. One day, you will look back and wonder how those days passed so swiftly.
Say yes, say no, but use "maybe" sparingly and only when you really do mean "maybe." Otherwise, kids may think "Maybe means yes if I whine enough."
You are always teaching by example.
Occasional silliness will not mean your kids don't respect you.
Follow your instincts. Somewhere, there will be a parenting book that says you're doing the right thing.
Of course every family and family situation is different. Not everyone has been as fortunate as I to have parents to teach by excellent example, or to have as wonderful a partner to share child-raising responsibilities. Nor am I a perfect mother - far from it. I've made mistakes, many of them. In spite of that, my kids are happy, successful adults, and my family is, without doubt, the greatest joy of my life.