Steps to getting your website:
Interactive elements
If you've decided you want to actively engage your website audience, you may want to think about raising your website to a level beyond that of just "static" pages. In general, all of these elements will require server-side scripting of some description, and nine times out of ten, a database such as MySQL. This means they will have longer development and customisation times, and consequently, will cost more. The rewards of a successful blog/wiki or forum can be huge - good word of mouth exposure, added search engine placement etc. However, establishing a new online community requires not just interesting content but an enormous amount of effort. It's not simply a case of setting up and watching everyone roll in.
Blogs
Blogs, or weblogs, are provided by lots of perfectly good companies these days - www.blogger.com for example. These are often free, but they have limitations. You may want your blog to be located at your domain name, or you might want to personalise it more than these companies allow. A lot of companies also require a blog to either be integrated into their existing site, or at the very least, have a custom template to match their branding guidelines, which can make these free offerings less attractive.
Wikis
Wikis are websites which are editable by everyone; www.wikipedia.org is the most famous example. They can be excellent for communication and collaborative working between different groups of people all around the world. The fact that anyone can edit them is a mixed blessing: occasionally you may get a destructive user who creates havoc, all of which has to be repaired (rolled-back) by an administrator. They can of course be closed down to select groups: Doku wiki has excellent granular permissions, meaning you restrict whole sections or individual pages to a group or a single user.
Forums
Forums are designed for threaded conversations - linear discussions which can be tracked right back to the source. Like wikis, these can serve as excellent community or collaborative environments. They often have permissions, which, like wikis, can be used to enforce some sense of control. Forums generally place more emphasis on the individual - your user name and identity feature more prominently in a forum than in a wiki.
Surveys
Online surveys can be useful to gauge customer responses, and if you offer some incentive, such as a prize, they can act as a draw for traffic to your site. Once a survey application has been created for your website, you will be able to create your own surveys and questionnaires however often you want at no additional cost.