....lets say you got a domain that you intend to build later, but in the mean time you put some useful information up about your site on the home page and start building up one way link to it. Is there any benefit in doing this?
You want link one your bweb site with other? Where are they hosted. At least diffrent C class Ips neded
Yes there is a benifit and it is a very sensible thing to do. In my experience it takes about 8-12 months to get a new website ranking for a competitive term, so if you can build links to your site now and if in a few months time you want to do something with it you will be better placed to.
If the theme of your site will not be changed later - yes it makes sense. Domain age, time in the search engines and link age play an important role in ranking factors.
...a chance of getting banned for doing this? Poodle may think that your one page website has over a period got X amount of one way links and this is search engine manipulation since a one page site cannot be that important. So even before you can launch your official site you are either thrown at the back fo the SERPS or you are banned. Can this happen?
sometimes i just buy new domains through some simple but related content on it link from couple of places and start building sites after 6-8 months when the site has aged and i have free time.
If you've got links pointing to your home page, then that page will benefit as long as the links are not blocked from passing PageRank or otherwise being followed. (This is something I've done from time to time, though I've always made sure the information on the home page described what the site would be about when it launches, and the sites were always non-commercial in nature.)
Yes, if you believe in sandbox theory. But, I would spend more time making the site (if I didn't have anything, yet) then getting backlinks for nothing but a landing page.
Unless you are some marketing genius who can generate a frenzy based on anticipation of something awesome coming to your site, you are going to have a hard time finding folks to link to a one page "site coming soon" landing page. It would be much better to get a portion of your site up and running and start building your backlinks as you build the rest of your content. As long as you are mindful of your site's file structure there's no downside to building and marketing at the same time.
Depends where your trying to get the backlinks from, for example if you submitted to some web directories and they saw that your site was not finished and lacking in true content they would most likely reject it.