I brought my cat with me last year, the quarantine procedures are as follows:
1) Make sure you have all export permits and vaccinations from your country, then get an import permit for Singapore as well as a reservation for space in the quarantine station. You can do that yourself or get a company here to do it for you. I can give you the details of the company if necessary. It costs about S$300, but saves you a lot of trouble when moving here, at least you know that your pets are taken care of.
2) For cats, there are 3 types of "accommodation": The first is the normal one for S$300 for the entire time (30 days), meaning it is quite hot and humid which may be very difficult for the animal. The second is with a fan at S$600. The third possibility is an air-conditioned room which costs S$900. The cat is in a large cage in this room with about 20 other cats. As mentioned above, you can visit Mon-Sat between 2 and 4pm.
After having spoken with a couple of people who had had negative experience with the basic accomodation because the animals couldn't cope with the heat etc. I opted for the third possibility, and although it is more expensive it is definitely worth it. My cat was very nervous the first three days but then things became better.
If you need more information email me and I'll be happy to help.