Plenty of people in Europe are gluten intolerant, just like everywhere else in the world.

You can get gluten-free in most supermarkets in Britain.

Every supermarket in the Netherlands provides GF food. In restaurants however, things may be different. Lactose-free, yes. Gluten-free, not so much.

There is already a thread on here for which you can search called "Gluten free in Paris" but I am not sure how much of it you could use on another blog without permission. But you could certainly link to it.

No problems getting produce in Irish Supermarkets, pubs and restaurants

http://www.coeliac.ie/

In the Netherlands if you give a restaurant notice they will normally be able to provide a good gluten free meal.

My son's MIL has to eat gluten free and manages to eat out quite often without too much problem. She always asks about sauces and things if she hasn't been able to warn the restaurant before hand. She has travelled all over Europe and not starved yet.

Here is a list of restaurants which are especially Coeliac friendly: http://www.glutenvrij.nl/uploaded/FILES/02_NCVinfo/NCVinfo_aangesloten_restaurants_HA.pdf

And although this is a Dutch site it also has plenty of restaurants on clickable maps, in the Netherlands and Europe:
http://www.livaad.nl/Horeca.htm

Gluten free is hardly a novel concept in Europe. If you're going to blog about it, though, I suggest you do your own on-the-ground research and begin by learning the terms in the languages of the countries you're planning to visit.