You will be on the Portfolio page once you have logged into Mathjobs.Org. The actions available to you are presented as *links* across the top of the page.
Following are steps that most applicants will want to take as they get started:
Submit portfolio materials
The Portfolio link is where you create, update and submit your AMS cover sheet, cover letter, CV, publication list, research and publication statements, and any other items you may want to submit. For more details, see Portfolio on the User Guide page. Submitting portfolio data and documents does not mean you have applied for any job. Each job must be specifically applied for using the apply button on the jobs screen.
Search, view, and apply for jobs
Search the current open positions by clicking on the Search link and apply to a position by clicking on the Jobs link. For more details, see Search and Jobs on the User Guide page.
Update or withdraw your application, check on the status
You can update or withdraw your applications to Jobs, as well as checking on the Status of your applications. For more details, see Jobs, Portfolio, and Status on the User Guide page.
Experiment to learn more
Never enter TEST data into the "real" MathJobs. It is often impossible to delete such data. You will want to use the DEMO VERSION of MathJobs for this.
To try out all the features of the MathJobs.Org system without worry of having to later undo your experiments, utilize the MathJobs DEMO Server, which is accessible from the MathJobs.Org homepage. You can login in as different users (see the main page there for login info), but please do not enter any real data there.