Your members will be asked to provide some information about themselves when joining the community or editing their profile. Create some profile questions that allow them to describe themselves in a way that relates to the theme of your community. To reorder the profile questions, click on their names and drag them up or down. If you want to show different sets of questions to different types of members, you can create multiple "profile types". This is useful, for example, if you want your community to have "fans" and "musicians", each with a different set of profile questions.
You can allow your members to change their profile types from Member Level Settings. You can also change individual user's profile type from Manage Members settings.