So, you want someone to design your website, fill it with content, advertise it, and manage it once it is up and going. Sorry, those should be four different jobs. You can recycle the actual text of the job post that describes what the project is for as long as you change the job title and keywords where the job will be listed. Some freelancers may do more than one of these things, but keep in mind if a freelancer could do all of this by themselves, why would they not just do it for themselves and make more money by getting rid of the middle man- you.
Many times, the multi-job posts are also for writing e-books. At the minimum if you want to be a successful "start-up" publishing company, you need a writer, an editor, a formatter, a cover designer, and a marketer. Most marketers will get you started and then you would need to hire someone else to continue the work on a regular basis. The editor might be able to format and write, but it is nearly impossible to edit your own work well. Formatting should be the proofreader's job- who also acts as a second pair of editing eyes. Although one person could do all this for you, you will probably end up with some jobs done poorly.
I think many people believe they can use other people to set up a business they know nothing about. This is a falsehood. If you don't know what you are doing and you plan to hire someone to do it all for you, you will have no idea what you are looking for in a freelancer. This will lead you to post a variety of projects under one title. In addition, if you don't know what you need, you won't know the right person for the job.