You wouldn't need a college education to get into the country but to get a job, you will definitely need some sort of qualification.
I don't think Singapore is the kind of country and you could come in as a tourist and try to find a job whilst here. Although it can happen.
You may want to look at the following for ideas:
http://www.sg/careers/careersemploy.htm
http://www.thegreenbook.com/careers.html
http://www.jobasia.com.sg/
Good Luck.