It took me way longer than it should have to test my DNA for genealogy purposes. When I finally did, I was astonished to find that parts of my DNA match 51,891 other people who have DNA submitted tests on Ancestry. In the past couple years, I've been analyzing their trees, collaborating with them, and learning more about my ancestors through some of their research. This is the reason I chose Ancestry as opposed to another company. There are so many trees on Ancestry and that is how we make sense of the DNA tests.
AncestryDNA provided me with many leads and confirmed several relationships I had suspected but couldn't prove, but I soon realized I could learn even more if my father were tested. Because I am female, I didn't inherit his Y-DNA and it is known that fragments can be lost from one generation to the next, so his test would provide matches I didn't see. Sure enough, his test showed he has 73,785 matches on Ancestry! That's nearly 22,000 matches that didn't show up in my matches - 22,000 more clues and possible leads to follow!
My mother died 13 years ago, so we never had her tested, but her father (my maternal grandfather), was willing to be tested so I submitted his DNA, which should help trace his lineage eventually. Surprisingly, he has fewer matches than I do, with 42,921 to date.
Looking at their "Shared Matches", helps me label and identify many of the 50,000 matches on my list. It's an amazing system I highly recommend. If you've been tested, I recommend getting any parents or grandparents tested as soon as possible. If your father is no longer living or isn't willing to be tested, see if you can get a brother or uncle tested instead. Aunts, uncles, siblings, cousins, sons, daughters - each carry specific parts of your lineage. Sons inherit their father's Y-DNA so testing males is imperative. Meanwhile, girls inherit their mother's Mitochondrial DNA, which isn't passed down to sons (from what I understand), so aunts and daughters DNA are valuable for tracing maternal ancestry.