I'm going to answer this as best as I can. In fact, it is a full solution for any system you are likely to work on, ever, despite the fact I'm only 50% sure of what you need from your question. Anyway, here is goes:
- Take you system and break it down into individual tasks. (e.g. "Post a new job", "Store the job", "e-Mail users" etc).
- If you can't start these task - break those down into sub tasks, e.g. "e-Mail users" could become: "Get list of recipients", "Get e-mail template", "fill e-mail template with job info", "populate e-mail recipients", "Send email via smtp" or somesuch
- Repeat steps 1 & 2 until you feel you cans start and get going. Your plans may change as you do this, that is normal as designing a system is hard, apply the same principles if/when you get stuck.
Your question as it currently stands reads: "How do I write this whole system", no-one is going to do that for you, it is simply too much work and there are too many design decisions only you or your team can make. You might be able to find frameworks to help reduce the work you need to do - I dare say they are several for this task, not all are free. You then have the option of integrating into your system.
Once you've started coding, you will hit problems, google first and if you can't get help there then aske here. Simple, "atomic" questions are more likely to get answers especially if you provide code and state what it is that isn't working. It is also OK to say something like "I need to send an e-mail via an SMTP server, but don't know where to start, I've tried googling x,y, and z but couldn't find what I'm looking for. How do I start/what should I search for".
Submit an article or tip