Both wrong.
You only need a tourist visa to arrive in Singapore.
Then you need to find an employer who wants to give you a job.
If you get the job, then the employer has to file for a Work Pass (various levels, WP, S, Q, P1, P2 and another special one called a PEP). All of these and their respective requirement can be found here:
http://www.mom.gov.sg/publish/momportal ... _pass.html
When the potential employer file the application, they have to hope that they can convince the MOM WHY they need to hire a foreigner (especially if there are sufficient local/PR with suitable qualifications/esperience already here).
You cannot work UNTIL you have and IPA (In Principle Approval). Once that is issued, then you get to take the IPA and report to the relevant authorities to have your pass issued (it's only good for the one employer and you can only work for one employer at a time).
Once you have your work pass in hand or the temporary work pass (not always given) you can report for duty with the employer.
sms