How do you guys know so much about your family history? I've recently gotten into the ancestry.com site, but its basic birth, death, marriage stuff.
A combo... We had old family stories, and old diaries which helped bunches with understanding why they did stuff. Some of them are AWESOME! I had one ancestor that hired himself out as an upper rank mercenary to Napoleon. He slaughtered and plundered and got bunches of goodies by doing bad stuff, but then was at Waterloo, on the loosing side. Oops.
But ancestry has excellent stuff, I have used them extensively to get the facts straightened out. Marriage dates etc. But you need to do it slowly and carefully and don't get tempted to add everything that pops up or that other people have found. Lots of that is wrong. Kids swap names all the bleebing time! I had one family that gave me fits. My ancester on that side had ALL of his relatives die by the time he was 12 so he was fuzzy as to family history... Duh. The five brothers that all came to Texas with their wives and kids in the 1800s all of the adults died within 5 years. The men all had three first names, with many repeats in the names, and they changed which name they were called by, especially if a kid named Chistopher Frederick Johann would die, then his younger brother Frederick Johann Christopher would now go by Christopher!

Anyway. It also depends on where your ancestors lived. The records that the puritans kept rocked! None of the family stories from that line made it down to me, but a crazy amount of info and stories and "the founders of our town" stuff was written down. All of the cool stories I know from those folks I found through ancestry. They have photos of original wills from the 17 hundreds and even some from the 16 hundreds. Many of the tiny towns had aldermen and recorded everything that happened. Truly everything.
Texas is more difficult, but they still recorded land transactions and the taxman made it to all of the more populated areas. I spent a crazy number of hours looking through land transactions and the tax roles, mostly on spools that need to be read by using these machines.... (The names of those things escape me... But the point is they are not on the internet, they were at a very large ancestry library in Houston).
Looking at the original documents is best because there are SO MANY transcription errors it is crazy. Also, until about 1900 no one spells their name the same from one year to the next.

I still have two grandfathers that died in Texas and I can NOT find where they are buried!

Ancestry has the original images of the censuses. They ask different things different years, but some years the questions are stellar. Like "number of live births", " own your own home" "have a mortgage" "own a wagon and head of oxen". I also love the farm schedules. They list not just number of acres owned but how many chickens, bees, apple trees, kind of potatoes..etc. For livestock they listed how many they lost that year to rustling or predation. The info from the farm schedules are awesome.
You don't want to look just at the Federal census but the local census done by the state. Fun stuff.