I've spent the past month or so going back in my family tree trying to verify that the lines are correct-- that I haven't accidentally followed the wrong family or anything. That happens a lot when you rely on some random person's personal genealogy information.
You need to have records and sources as evidence that your tree-- and the people in it-- are correct.
To that purpose, I've been trying to hunt down records of my ancestors from New Hampshire. They're proving far more difficult to track down than my Massachusetts ones, who have excellent and thorough records dating back to the 1600's. New Hampshire historical vital records, on the other hand, are not easy to find, at least not online.
Thankfully, I stumbled upon a great FREE database (I'm all about "free") called FamilySearch.
Here I was able to access records for, among others, my great-great grandfather, George Bailey Palmer, his wife and my great-great grandmother Mary (Purinton) Palmer, and her father Isaiah F. Purinton.
Above is a picture of a picture of Mary Purinton Palmer (the actual photo is unfortunately lost-- temporarily, I'm hoping). On the back of this was written, "Mary Olivia Palmer, 1851-1898. Wife of George Bailey Palmer and mother of George W. and Frank Bailey Palmer. 1926." It's only thanks to this inscription that I know who this was and had enough information to trace her lines back.
Death records, which seem to be the most plentiful in this database, give all kinds of information: exact birth date and birth place, names of parents (often including the mother's maiden name), death date and death place, cause of death, and burial place.
I found that, for birth records, these old records sometimes list the person's age at death instead of an actual birthdate: for example, Mary Purinton Palmer was "46 years, 8 months, and 4 days" old at the time of her death, which was July 13, 1898. It just took a bit of math to figure out that she was born on November 9, 1851.
I also discovered that she died of cancer, though the record didn't specify what type. More interestingly, her father Isaiah (1818- 1890) is listed as having died of "cholera morbus" at the age of 71.
According to Wikipedia, "cholera morbus" could refer to either actual cholera or any general form of gastroenteritis.
A neat thing about some of these genealogical databases is that you can see and download the actual documents, not just see secondhand the information in them.
This database isn't just for New Hampshire, by the way, but appears to have records from all over the world.