Family trees for some families have been done and completes years ago, though none are really ever done. You can only go back so far before there is simply no more information that you can use. If that is not the case in your family, you may be searching for your ancestors by looking up vital records like birth, marriage, divorce, and death records. It might also be helpful to know where your relatives are buried when searching for more data.
There are going to be times when you cannot find what you need to verify that someone was in your family or not. There are many common names, and if you have one in your family tree, your search is a bit harder than most. You need to be sure that you have the right person by verifying dates through vital records. You can also very some information by getting birth and death dates from tombstones. Finding them does not have to be hard.
You can always look in local cemeteries when you first start out. Some like to go in person for various reasons, and it is often great to find what you need on your own. If you have an area where many recent relatives have been buried, you have a great place to search for others that you do or even do not know about. This can only take you so far, however, unless you family has been in the same place for centuries. This is nearly impossible, as you may have guessed.
Your family tree does not have to remain incomplete if you cannot find what you want when searching locally. There are some great resources that you can find online if only you know where to look. Instead of guessing, start with the obvious. Go to the many genealogy sites that you can find online and see what they have for cemetery records. You should be able to search by name to see what comes up along with whatever information was found on each tombstone.
If you are having a hard time in your search when trying to find a nearby cemetery, or one that is far away, you can find a site that can look up the records that you need if they can be found anywhere. This can happen for you in minutes if not seconds. It can clear a path through your tree that has been blocked, or take you in a whole new direction.