In your third picture, it looks like you have multiple plants in the same pot, here. You could divide them into their own, individual pots (come warmer weather, that is). Your little monster is otherwise incredibly charming!
I would suggest a north- or south-facing window for your friend (as these directions seem to best get along with my own spiderplants, of which I have seven or eight mature plants -- one of them is on the line of maturity -- and 3x - 4x as many juveniles, currently).
As to watering -- I water, personally, when the dirt is dry to the touch. I'll usually push my finger into the dirt a bit, so I'm not just feeling the topmost layer. Dry? Then that plant gets some water. I'm also a fan of spritzing plants, every so often. If nothing else, this seems to help keep spideys a bit cleaner and happier.
Spiderplants are pretty sensitive to flouride (and a few sources have suggested they're not happy with boron, either). If you can, I'd avoid watering with city tap water. Some folks claim flouride doesn't effect spideys, but I've noticed that tip burn on my own spideys lessens significantly if I water with filtered water instead of city water. Granted, this doesn't solve tip burn, but my plant pals tend to have less of those dead tips if I'm following this guideline.