Recently, I presented to the Genealogical Society of Okaloosa County, a brief overview of what's involved so far as online family tree websites are concerned.
The issue is, whether each of us have availed ourselves of this opportunity. The presence of your family tree, online, is sure to catch the interest of those who may be researching the same family lines. With that interest, it is entirely possible that you will discover the existence and whereabouts of extended family members, like cousins, for example. These individuals can enrich your family history search with additional family photos, family stories, and of course, the proof we need to document our family's vital life events. Identifying descendants of your ancestors is also the first step toward planning a family reunion.
Here is the presentation, with many links embedded. Hopefully, it will answer some of your concerns and address your questions. If not, feel free to contact me. There are several book publications on this topic, as well as all kinds of software and Internet help, available.