You've been given the main passport info page.
If your husband's passport was issued less than 15 years ago, he should qualify as a renewal. Brings down the cost and increases the easy factor, b/c you only pay the passport fee for him, not the other fee, as everything is just mailed in. That's if he has the old passport still, of course. (they basically allow you 5 years after the p'port expires to be a renewal)
Everyone has mentioned the important factors for the other parts...best if you all go together to the PO or whichever place (if you go to a non-post office, be SURE you call them to make SURE what fees they have and how to pay those fees!), but if you can't have both adults, make sure the absent adult has the forms notarized giving the other adult permission to get them passports, etc.
I myself just renewed not 2 weeks before the end of my 15 years, and for the almost 5 years of NOT having a valid passport, I felt stifled! I couldn't stand not being able to roam freely! I love having a passport, even without firm plans to go out of the country.
Took us probably one month from taking DS to the PO to get his passport process started and from mailing in my forms to getting the passports. Well under the 4-6 week processing time. But again, we were not under any travel stress; we just wanted to get them. (beating the clock with my renewal AND we got them in just days before the prices increased to the level they are at now)