Hi,
for beginners, Andorra is good, since there are plenty of green/blue rated slopes. It tends to be a cheaper than Switzerland/Austria too.
To do it the cheapest way, its best to book your flights and accomodation yourself and hire the skis/boots when you get there.
However if this is your first time skiing and you're not sure what to expect, it might be easier to go with a tour group (like Panorama, Crystal ski etc), since they can book it all and take away the responsibility from you.
For ski clothes, you can hire ski suits in Ireland (in The Great Outdoors I think). Also, in Dublin, Pamela Scotts ski shop have very competitively priced ski wear. Cant remember exactly what street the shop is on - but its parallel to Grafton St, going towards Georges St.
Enjoy your hols.