When creating a guild you need to come up with a guild name and also select a number of settings:

Guild type:

• Public, accessible to all;
• Private, admission only by invitation, not available via the search.

Minimum level for joining:

• Players below this level will not be able to join the guild. 

The player who created the guild automatically receives the title of the Boss.

You can always modify any of these attributes via the 'Edit' button.