Gluten is the name given to a group of proteins (also known as prolamins). Reactions to this group of proteins are not considered to be a true IgE allergic reaction.
Coeliac disease (European spelling, known as Celiac in North America) is an autoimmune disorder where the body reacts to gluten in foods consumed and damages the gut, causing poor absorption of foods.
Despite not being an allergy gluten is usually included in food allergy lists as it needs to be labelled on food in Europe as there are large number of sufferers worldwide.
I have put together some more comprehensive resources at http://www.allergyresources.co.uk/Gluten.php
The allergy resources page for gluten covers the key allergens, which allergic syndromes are linked to this allergy and other foods which are commonly cross reactive with gluten.
There is also regularly updated links to useful websites specifically for gluten allergies and the latest research papers on the topic.
If you have multiple allergies and are interested in how they are linked or want to find out more about food allergies outside the usual top 14 then you can follow me on Facebook or Twitter, where I share a food allergy card every day of the week.