Thanks to youngtugs original link I found myself at the ISOGG site and have been doing a crash course in dna testing
Some really basic (ie not too complicated for me!) but interesting articles, and I now understand some of the acronyms I've seen scattered around the threads here.
Thanks also for your input davidft and sugarfizzle - yes, I think my mother is thinking that she will find relatives of some description, I'm not sure even she knows exactly what she thinks will happen.
We've been doing our family history for some time now so have quite extensive trees for both my mother and father, all backed by lots of paperwork. Both trees are on Ancestry because I used to subscribe but haven't been updated for some time as I now tend to work offline.Thinking about it while I was reading some of these articles I've realised that we have a major brick wall on each side of the family that we have been chasing for years (including on rootschat) and have never broken down, and dna testing may actually help us with these.
On my father's side I can't go back beyond about 1820 (Scotland) as there are no paper records. However, I am sure that some of the families around will be cousins/aunts/uncles, I just can't link them up. If any of their descendants have taken a dna test it might help point me in the right direction.
On my mother's side her grandmother seems to be parentless (Wales). Again lots of people have been researching for years and someone has now come up with a possibility of a family but there is nothing concrete. So this could posssibly help to resolve that.
Ethnicities don't really interest me - our families have been English/Welsh, Scottish/Irish for the last six or seven generations. Whatever ethnicities show their faces are okay with me but I don't feel the need to go looking for them.