This is a customized site, and it requires some degree of development work.

But if I download the free version of MonoX, it doesn't give me the complete source code...only aspx pages
Where should I start looking if I want to start a job search site based on MonoX ?

any advise ?

Actually you don't need the complete source code to add new functionality (which is what you will do in your scenario), you need it if you want to change the existing functionality. It is easier to work if you have the source, but it is not impossible to do it. You will need to consult the tutorial and API documentation.

Thank you

I just read the API document which is very good and covers all the information about the monoX libraries

Is there any way monoX can be used as a job search website with the current available functionality without customizing the code ?

You will not have to customize the existing core of MonoX, but you will have to implement your own functionality on top of it.

Any advise, how to get started in order to accomplish what Im looking for ? sorry I am new to MonoX...

You can start by opening a new project - http://www.mono-software.com/blog/post/Mono/95/Building-a-custom-ASP-NET-project-based-on-MonoX/ - and building your own Web part - http://www.mono-software.com/blog/post/Mono/95/Building-a-custom-ASP-NET-project-based-on-MonoX/
As MonoX Web parts are ordinary ASP.NET controls, all your existing ASP.NET skills will be useful when working with MonoX.