First you have to decide what you want to know. A paternal line? A maternal line? As others have said the paternal yDNA goes from the man tested through his father, grandfather, and up the line. Only males can be yDNA tested. If you have a family name that you want to trace, or the possible ancestry on a particular male line, this is a good way to go. The maternal DNA, mtDNA (mitochrondrial DNA), goes from the woman to her mother, grandmother and so on up the direct line. This is not a good way to find female ancestry because the mtDNA mutates very slowly and may match someone who is related hundreds or thousands of years ago, and you won't know how. It will give you an idea of your Ancestress' distant maternal history as far as where they came from and where they passed through. Both men and women can be tested for this, as they each get mtDNA from their mothers. If you are seeking to find who else in the world you are related to, then autosomal (aDNA) testing is the way to go. My brother and I have both been tested at FTDNA for the basic y and mt DNA, and then to 23andMe for the autosomal. We were hoping to find some clue to our unknown great grandfather's line. Now we have had a couple of cousins on that side tested. Nothing yet. Autosomal DNA testing will give you the haplogroups (types) of y and mt DNA the person tested has, except for women who only have the mt. A $100 test won't tell you much. I recommend that you research very carefully the companies that do DNA testing. Most of us who are into this seriously have seen the disappointment of those who tested cheaply, and then didn't get enough results to compare with others. DNA testing can get very expensive when done seriously. Explore the websites, and the tutorials they offer. It is a new jargon you will have to learn, but there are Forums online that will help you as you are going through the Newbie stage. There will be no quick answers. The thing to remember is that all of this is still in the research stage, and there is much to be learned yet, both by the tested and by the companies. It can be rather time consuming, but some of us have become DNA junkies by now. It is exciting when you find someone predicted to be a fourth cousin, actually shares a portion of DNA in common with you, and maybe even your brother and cousin, and there is a common name in your ancestry. So, do your homework, check out the companies, and join some of the forums. (you can google them) Then lurk for a while until you get the gist of what is going on. Then decide on the type of testing. Disclaimer: I am not necessarily recommending the companies above, but used the names as we had tested with them. "rwalker"