The first step with Dropbox for Business is to get everyone on your team. You’ll need to invite your team members so they create their own business accounts. To invite someone, simply:

You can also invite people by going to your admin dashboard. Under Current members, click Invite members. Learn more about the admin dashboard.

Don't worry if your coworkers already have Dropbox accounts. People you invite can convert an existing Dropbox account to a Dropbox for Business account or create a new account to join the team.
Dropbox for BusinessThis article refers to a feature unique to Dropbox for Business. Dropbox for Business is aimed at projects, groups, and other organizations that want to share the same Dropbox storage quota with all of its members. If you're interested in learning more or want to sign up, visit the Dropbox for Business webpage.