wordpress: managing settings
Site Title and Tagline: These are generally called from the banner area of most themes. However, themes are free to place these wherever they like, or not use them at all. For SEO reasons, it's a good idea to include the site title in an H1 tag in your theme.
WordPress Address and Site Address: These let you establish the URL of your site, which may be simply a domain name (http://example.com) or a domain name and path (http://example.com/blog). The Site Address field is usually the same as the WordPress address, but may differ if you don't want the WordPress installation files living in the document root of your main web site.
E-Mail Address: This is the address of the site's main administrator. Even though each User in the system has their own email address, this address will receive comment moderation emails.
Membership: In most cases, you'll want this turned off. If enabled, users will be able to sign up for accounts on the site. This is generally useful only in two cases: 1) If you only want to accept comments from registered users, or 2) If you want to accept content contributions from the community.
New User Default Role: if the Membership option above is enabled, this will set the role for newly signed-up users. Set this either to Subscriber or Contributor. It is extremely rare that you would want newly signed up users to have a higher role (and it could be a big security risk).
Timezone: Be sure to set this as soon as you install a new site, since it will affect the timestamp of all posts you create in the system. WordPress will look at the system clock of the server it's installed on and adjust timestamps accordingly if necessary.
Date and Time formats: These are self-explanatory.