The most important part of dressing for outdoor learning is wearing the proper layers.  Also teaching our kiddos how to regulate their body temperature by removing or adding a layer based on their activity level or outside temperature for their comfort.  Proper layers consist of a base, mid, and outer layer.
Base Layer:  Worn next to the skin and under clothing. This layer should be sized to fit and not sized up.  The purpose of this layer is to keep the body warm and dry by wicking any moisture away.  Ideal fabrics for a base layer is a thin/light weight wool or high tech poly material.  Cotton garments are NOT ideal as a base layer.  That includes socks.  Cotton socks will NOT keep their feet warm and dry.  We strongly recommend investing in merino wool or a high-tech poly socks as a base layer.
Mid Layer:  Worn over the base layer and acts as an insulator.  Mid layers tops can be a zip fleece/hoodie, or a light weight jacket like a thin down/puffer jacket. Mid layer bottoms can be a fleece lined jogger/pant, or a loose wool legging.
Outer Layer:  Worn over the mid layer to insulate and protect the body from the elements.  This layer should be waterproof, windproof, and insulated in order to keep the body warm.

Backcountry (Outerwear, footwear, & accessories)
Columbia Sportswear (All layers and accessories)
L.L Bean (All layers and accessories)
Outdoor School Shop
REI CO-OP  (All layers and accessories)
Sierra Trading Post (wool socks, mid layers and accessories)
Uniqlo HeatTech and Airism (Base and Mid layers and accessories)

As with most things with children, the most effective rain gear for kids is the gear they are most likely to wear.  Rain gear typically comes in 3 different styles; a one piece suit, a two piece jacket and pants with a bib or suspenders, and a two piece jacket and pants set.  Determine which rain suit style and accessories best work for your kiddo.  Some kiddos prefer wearing a rain hat rather than wearing a hood, or they may prefer wearing a one piece suit rather a two piece rain suit.  Many retailers make fashionable outerwear but the technology does not always meet the grade.  Make sure the gear you are purchasing is waterproof and NOT water resistant. 

Backcountry (Outerwear, footwear, & accessories)
Bogs (Footwear)
CeLaVi (Rain Suits)
Columbia Sportswear (Outerwear, footwear, & accessories)
Kamik (Footwear)
Oaki  (Outerwear & Footwear)
Outdoor School Shop
Rei CO-OP (All layers, footwear, & accessories)
Reima  (Outerwear & accessories)
Sierra Trading Post (Outerwear, footwear, & accessories)
Therm  (Outerwear )
Tuffo (Rain Suits)

Winter and cold weather outerwear is very important in safely learning in nature. 
There are so many cute winter designed clothing for kids that look like puffy and warm  but not all materials are made to keep our kiddos dry and warm.
Waterproof and insulated or a high tech poly are important key words to look for when buying protective winter gear.  

Backcountry (Outerwear, footwear, & accessories)
Bogs (Footwear)
Columbia Sportswear (Outerwear, footwear, & accessories)
Kamik (Footwear)
L.L Bean (Outerwear, footwear, & accessories)
Oaki  (Outerwear, footwear, & accessories)
Outdoor School Shop
Rei CO-OP (All layers, footwear, & accessories)
Reima  (Outerwear  and accessories)
Sierra Trading Post (Outerwear, footwear, & accessories)
Target All-in-Motion Brand Snow Bibs or Pants (Seasonal)

Randolph has a wonderful tradition of hosting a campout for the Upstairs (Upstairs Neighborhood & Carriage House) friends and their grown-ups.  Some families are seasoned campers and already have tents, sleeping bags, etc... for others, we may need some recommendations on gear.  

Aldi (Seasonal)
Backcountry
Coleman
REI Co-op
Sierra Trading Post