Welcome to the world of chameleons!
I have been keeping/breeding/hatching chameleons and other reptiles for over 25 years. My veiled females generally live to be over 6 years of age and often older. The males also live longer than that. I live in Ontario so my climate is somewhat like yours. This is what I do...
Hatchling veileds I start off like this....
http://chameleonnews.com/02NovHorgan.html
By the time they are 3 or 4 months old they are in cages (one per cage) that are 18" x 18" x 24".They usually have screen lids and some have screen doors or else they have vents in the front. I have kept some in all glass cages that have screen lids too...and as long as the lights are placed correctly and there is no water allowed to lay stagnant on the floor of the cage its fine.
Exposure to proper UVB, appropriate temperatures, supplements, a supply of well-fed/gutloaded insects, water and an appropriate cage set-up are all important for the well-being of your chameleon. As you can see in the pictures in the site above, the cages are lit/heated by a double fluorescent tube setup. I use one regular white household fluorescent tube in the fixture along with one Repti-sun 5.0. I slide the cages forward when they have chameleons in so that one end is warmer than the other. Once they are in the 18" x 18" x 24" cages the lights run across the back half of the cage. (I don't use the plant light fixtures...just regular 4' fixtures that I buy at places like Home Depot, Canadian Tire, etc. that hold two tubes.) If the cage is still too cool I add (in one corner, next to the fluorescent fixture) a regular incandescent household light in a domed fixture. The wattage is whatever is needed to make the basking temperature correct. (For male veileds over 5 months of age, mid to high 80's or even into the low 90'sF.)
You can "decorate" the cage with an assortment of vines, branches and greenery...live non-toxic greenery that has been well-washed, both sides of the leaves is recommended, especially for veileds since they can/do eat vegetation as well as insects.
As long as the veileds are well-watered, its not critical to have high humidity. I definitely wouldn't have it humid enough to make a mist on the sides of he cage. IMHO that's asking for health issues. I mist the baby cages a couple of times a day. I don't use a dripper until they are a couple of months old...babies can aspirate large drops of water into their lungs and die from it.
Appropriate cage temperatures aid in digestion and thus play a part indirectly in nutrient absorption. Temperatures needed can vary with the species and the age and sex of the species.
Exposure to UVB from either direct sunlight or a proper UVB light allows the chameleon to produce D3 so that it can use the calcium in its system to make/keep the bones strong and be used in other systems in the chameleon as well. The UVB should not pass through glass or plastic no matter whether its from the sun or the UVB light.
The most often recommended UVB light is the long linear fluorescent Repti-sun 5.0 tube light. Some of the compacts, spirals and tube lights have caused health issues, but so far there have been no bad reports against this one.
Since many of the feeder insects have a poor ratio of calcium to phosphorus in them, its important to dust the insects just before you feed them to the chameleon at most feedings with a
phos.-free calcium powder to help make up for it. (I use Rep-cal phosphorus-free calcium).
If you also dust
twice a month with a phos.-free calcium/D3 powder it will ensure that your chameleon gets some D3 without overdoing it. It leaves the chameleon to produce the rest of what it needs through its exposure to the UVB light. D3 from supplements can build up in the system but D3 produced from exposure to UVB shouldn't as long as the chameleon can move in and out of it. (I use Rep-cal phos.-free calcium/D3).
Dusting
twice a month as well with a vitamin powder that contains a beta carotene (prOformed) source of vitamin A will ensure that the chameleon gets some vitamins without the danger of overdosing the vitamin A. (I use herptivite). PrEformed sources of vitamin A can build up in the system and may prevent the D3 from doing its job and push the chameleon towards MBD. However, there is controversy as to whether all/any chameleons can convert the beta carotene and so some people give some prEformed vitamin A once in a while.
Gutloading/feeding the insects well helps to provide what the chameleon needs. I gutload crickets, roaches, locusts, superworms, etc. with an assortment of greens (dandelions, kale, collards, endive, escarole, mustard greens, etc.) and veggies (carrots, squash, sweet potato, sweet red pepper, zucchini, etc.) BTW..veileds can eat/be offered all of these greens and veggies and even a small amount of fruit (apple, pear, berries, melon, etc.).
Calcium, phos., D3 and vitamin A are important players in bone health and other systems in the chameleon (muscles, etc.) and they need to be in balance. When trying to balance them, you need to look at the supplements, what you feed the insects and what you feed the chameleon.
Here are some good sites for you to read...
http://chameleonnews.com/07FebWheelock.html
http://web.archive.org/web/20060502...rnals.com/vet/index.php?show=5.Vitamin.A.html
http://web.archive.org/web/200406080...d.Calcium.html
http://www.uvguide.co.uk/
http://raisingkittytheveiledchameleon.blogspot.com/
http://web.archive.org/web/20060114031124/http://www.adcham.com/