I second Wind in My Hair on the CC courses. They are not expensive and if it's basic cooking that you want, you'll be happy enough with them.
If you want to have a nice day out while learning how to cook, Ruqxana (
http://www.cookerymagic.com/) runs a Malay cooking class at Pulau Ubin. She also does organic farm cooking and daily home cooking (simple Chinese, Malay, Thai, Indian etc dishes) classes in her home, if I'm not wrong.
I've been to Shermay's. The instructors are good but I'm not fond of demo classes, I still prefer some hands on. For that I prefer the cooking classes at at-Sunrice. Plus Fort Canning's a lovely setting.
If you want to learn how to make sushi, Tempura etc, I would recommend the California Sushi Academy in Singapore. It's at Liang Court at Clarke Quay.
There are other schools like Palate Sensations and Coriander Leaf, but if you're just starting out, I still think the CCs will be best in terms of range and cost.
Cooking is easy once you get both the Art and the Science of it.
Good luck!
Je pense donc je suis. Le reste du temps, je ne suis qu'une fleur.