2 or 3 pairs of skiing socks- proper ski socks have extra padding where you need it the most and are worth getting! Warm and ideally waterproof jacket and trousers or sallopettes. Extra padding is good for warmth and protecting you from bumps and bruises and most ski wear is padded, but if you don't want to splash out on a new ski outfit then normal outdoor winter waterproofs with enough layers underneath will be fine.
At least three layers - thin thermal layer or t-shirt made of wicking material rather than cotton next to the skin, a mid weight fleece and a thicker fleece.
Ski jacket and trousers or sallopettes - a padded and thermally insulated jacket and trousers made especially for skiing are the best choice as they will have padding in the right place, be warm and have useful things like lift pass pockets. If you don't want to invest in full ski gear for your first trip then a quality waterproof jacket and trousers will be fine as long as you have enough layers underneath.
Fleecy trousers or thermals to wear under your outer trousers
Gloves, hat, neck warmer or ear warmer. It's worth getting decent waterproof warm ski gloves or mitts. A buff is a good essential as it can be worn under a helmet, as a scarf or even as a powder protector in blizzards over your face.
Helmet we wouldn't let our children ski or snowboard without a helmet these days so why not apply the rule to adults!? It could save your life. You can hire helmets in resort or buy yourself a trendy lightweight comfortable one.
Rucksack to carry spare sweater, waterproofs, packed lunch, water bottle, and other bits and pieces.
Good sized water flask or a plastic water bottle. A Platypus or similar water system is also very handy.
Sun screen – the sun is very strong in the Alps so please bring factor 50 for your face and for all children.
Lip salve with sunscreen
Sun glasses - you should make sure they wrap well round your eyes at the sides to protect you from snow glare from the ground
Goggles or ski mask – good quality goggles are invaluable on snowy days.
Sun hat or cap for warm spring ski days.
Duvet jacket - not essential but serves as a good lightweight warm jacket for those frosty cold days.
OTHER USEFUL THINGS
Slippers are so nice for feet in the evening.
Camera, spare film or memory card and batteries.
A small sit mat or bit of old camping mat - not essential but good for a bit of comfort when picnicking on the piste.
Swim suit boxer short style swimming trunks are not allowed in French pools