Hi there.
A. What is the salary for an office worker (local employee). $ 1,000 or more?
Depends on experience and qualification but yes $1000 is ok for a seychellois, but such fee will not suffice for an expat.
B. What is the cost of renting an office of about 50 m2. Where can I find ads (website address)
50m2 is one hell of an office block. Not sure I can help with that one, we don't have websites that advertises such either
C. Please web addresses where you can give notice of the work.
Most people advertises in the local newspaper and some on Facebook as we don't have a primary advertising area. There are few notable websites such as http://seyjob.com/ or http://www.dir.sc/ , you can check those!!! Hope that helps!!