Once you've created a job posting in your account, you have two different ways to view it from an applicant's perspective.
From your dashboard, click on Your public URL which is located directly below your company name. That will take you to your company's job listings (a.k.a. careers) page where you can view all active positions with summary text. To view the complete job description for any of your active listings, just click on the job title.
From your dashboard, click on the job title of the job you want to view. On the next page, you'll see directly below that job title a unique job link, or URL, for that job. Click on it to view the full job description. This option will enable you to view job postings that are "hidden" and, therefore, not on your careers page.