Hi Raine,
Taking landscape photography in color and/or B&W are nice. It'll be best to shoot with a medium format camera like Mamiya SLR/TLR, Rolleiflex TLR, Seagull TLR, Yashica Mat TLR, Hasselblad SLR, Linhof Technorama 612/617 panoramic camera, Bronica SLR OR a large format view camera like Shen Hao. Medium & large format roll films give better tonal gradations and other details than 35mm, especially in B&W. Books to recommend will be Charlie Waite's
In My Mind's Eye and
The Making of Landscape Photographs.
Taking landscape at night is not that impossible but most likely during the sunset time period which most photographers do. When night falls all colors are flushed out as more shadows set in due to the surrounding lighting. At this point you have to do long exposures and with some other accessoeries like flashgun, torchlight etc to compensate and show more shadow details in dark areas. I recommend you a photographic book
Night Photography by Andrew Sanderson.
Well based on the other guys' recommendations of the places, there are a couple that I have not been to myself i.e. Sungei Buloh Wetlands, Admiralty Jetty and Kent Ridge Park. Yes I agree that Punggol has quite a few places to explore for landscape photography. Pulau Ubin is one of the ideal places too. You can reach the highest quarry for a good birds' eye view. FYI there are 4-level platforms to the top. Better get a few friends to tag along.
Well there are some other desolated areas that are restricted for SAF exercise grounds. So better keep out of those areas. I'm not sure if this place is good - HSBC Treetop. You'll need lotsa walking to reach deep inside there from MacRitchie Reservoir. Think it's about 10km to-&-from.
Anyway hope my 2-cents worth of information help you in a way or another. Cheers mate!