I'm not sure if someone already mentioned this, but...
You can usually flower a plant after it grows to about a foot or a little over. As long as there hasn't been much spacing and stretching between the nodes. You'll know it can be flowered when you see the branches that usually come out directly on opposite sides from each other starting to branch out differently in relation to each other.
Like this (ignore the horizontal lines- it won't allow me to indent the characters properly without it):
--\|---
---|/---
---|----
As opposed to this:
---- | ----
----\|/----
---- | ----
Also, be sure if when getting reflective wrapping paper that it is the proper material. A lot of it is not Mylar, and will absorb a lot of light. So look carefully when buying- you should be able to see yourself almost perfectly in it when flat. You don't necessarily need Mylar, if you find it difficult to come by. You can just paint the inside of your growbox white, and it has almost the same reflectivity. Seriously.
Lastly, you need not worry about the smell for a long time. During vegetation, the plants usually don't have much of an odour at all, though it depends on the strain. During flowering, it's often very easy to mask the smell of one small plant. In fact, no one will probably even be able to smell it outside of the room it's in until it's almost ready to harvest. But you look like you know what you're doing as far as wiring goes, so prepare beforehand if it suits you. Air circulation is incredibly essential, especially early on, I've learned. Even a little bit helps strengthen stems more than you'd think.
You're well on your way.
~Ethno