Sandy
Forgot to mention my DNA experience. I did mine via FamilyTreeDNA. I was lucky but for most people it would be disappointing. They place you in what is called a haplogroup, of which there are about 20 main ones for European males. If you are jsut in the main haplogroup it is unlikely to tell you much. For example my main group was R. If I had just been that and not in any of the subgroups it would have told me I was related to half of the males in Europe. Not very useful. As it was it turned out I had a rare haplogroup called R1B1C7 - each extra letter represents a mutation which palces you in a smaller group. R1B1C7 is found in about 1% of Irish people all coming from Counties Tyrone and Donegal originally. It meant I was more than likely descended from a 5th Century Irish High King called Niall of the Nine Hostages. However, even though I got perfect matches with a couple of people on their database called Quinn and close matches with others it just means I have about a 50% chance of being related to them 200-300 years ago (or less). The chances of finding someone who has a family memory of a common ancestor is quite small. I have corresponded with a Michael Quinn who is Vancouver which has been interesting but our common ancestor is before the time when the records start.
Again not trying to be negative; maybe you will be lucky but it may not actually be that useful in locating an ancestor.
David