cj,

Check some of the following links:

http://www.ehi.ie/

http://www.horseridingireland.net/

http://www.aire.ie/

http://www.horsevacationireland.com/

http://www.horsesport.ie/affiliatesl.html

http://www.irishhorseriding.com/

I also suggest an Internet search with these terms: association of irish riding stables.

You must decide what area of Ireland you want to ride in. I can't personally recommend any of these because I don't do horseback riding. You will have to look through them yourself to find what best fits your situation. Look for those approved by Tourism Ireland.

Michele