Weebly is nice. Wordpress is excellent as well, but overall, it depends on what your needs are exactly. If you are soley advertising yourself as an investor/agent, than a wordpress blog may be sufficient as it creates more of a "profile" for yourself.
If you are selling just a single house, than I don't really see a webpage as necessary. There are so many places to post it up online in addition to social marketing, you can easily get the home sold without working an completely new website for it, not to say it would not help.
If you plan to go "corporate" by listing products online, services, links, pictures/etc and dive into the internet marketing world, you may want to go for a more professional approach. I agree with Christian, you may need to hire someone or just dive into learning ropes.