Hi Kath,
Well, I can guarantee that you will have a fantastic day at the ERO. I have said this before, but worth repeating, the staff at the ERO are very, very friendly and enjoy what they are doing, as can be seen by their enthusiasm for helping people and making sure they are welcome.
They will make sure you know how to operate the various readers, and I have seen them helping newcomers with their research too, I am very impressed with these guys (and ladies), and I think you will be pleasantly surprised.
It is nice to shower some praise on the people who can be bothered, a bit like this site, of which I place at a very high level of esteem. Me, I'm just the gardener. What??
Enjoy, and well done for the new family on the way.
Best
Kevan