First, yes that's my gallery, the waterfall photo is Niagara from the American side, thanks for the kind comments.
When there's low light, yes you can get more color with a longer exposure. You can also use the white-balance settings to bring in more color too. Daylight while balance tends to bring in more blues as well.
In the case of the waterfall photo, I think it was around a 15 second exposure, but the color is from the lights changing cycle. It's lit up from the Canadian side at night and the multi-colors were from it going from pink to yellow-ish if I remember correctly.
As far as information on photography, the internet is going to give you just as much info as any book. A few things to search for that will really help you learn more are:
White Balance settings
Lens Filters such as Neutral Density, Circular Polarizers, UV filters, etc
There's a ton to learn but eventually you'll start to see how everything kinda ties in together. Just going around and looking at other peoples photos really helps too, seeing what is possible, how the photo is composed, and what areas around you might be good spots for photography.