Family Tree Information
Depending on what kind of "family tree" you are planning to use to display your knowledge of your ancestors, there are a lot of places to get family tree information. If you are using a simple pedigree chart showing only your direct-line ancestors, then you need only birth (or christening), marriage and death (or burial) dates and places for your two parents, four grandparents, eight great grandparents etc. If, however, you want to include all your direct-line ancestors plus their siblings and spouses, with information about their education, occupations, military service, cause of death or other medical issues, then you will need to plan on a more elaborate set up and find more sources for information on your family tree.
There are many computer programs that will allow you to enter the data you find but I personally use Personal Ancestral File (PAF). Some prefer FamilyTreeMaker or Legacy. The advantage of PAF is that it is easy to use for all circumstances you may find in a family situation, and you can print pedigree charts or family group sheets implementing a variety of fields that you may want to display the family tree information you have found.
When you are researching information on your family tree, the best place to start is with yourself (and your spouse if you are married). Each event should be documented. Sources of information on your family tree could include such things as birth certificates, entries of christenings or other events in church records, entries in family Bibles, marriage certificates or licenses, obituaries or other items in newspapers, head stones in cemeteries etc. Other sources may lead you to this family tree information - sources such as phone books or city directories, migration records, prison records, county histories, military discharge papers, school records, apprenticeship records, photos and most importantly, living relatives. Censuses hold somewhat of a different spot in the scheme of things - they can lead you to sources of information but sometimes they will be the only source of information. Remember that the enumerator wrote down what he was told in response to his/her questions - whether it was correct or not. On rare occasions, the enumerator made some editorial comment like the woman who was enumerating a female-headed household in a large city in the eastern United States in the mid-1800s. In the column beside the woman and her children, she wrote "Husband walked out and never walked back".
Do not accept indexes as the sole source of information. ALWAYS go to the original source. If you are looking at a family Bible for family tree information, check the publication date against the dates written inside. If the book was published a number of years after the events purportedly took place, then memory might not be so reliable. If you find a written family history, check the sources and documentation. A reliable author will give you enough family tree information that you can go back to that source and find the information yourself. And be prepared to receive conflicting information. At some point you will need to put all your sleuthing talents to the test to determine which date or place or person is correct.