2 Places I've worked we've done the following.
Single Common A/C
- Create a common email-distribution group (myteamonazure@mycompany.com)
- Register this mail address as an MSN Passport
- Use it to sign up with Azure.
Pro's: Everyone on the team gets mails regarding the account.
Con's: If someone leaves the team, we need to change the account password.
Individual accounts
- Let each person signup with their own account. (Mandate it must be their company email... not personal msdn passport)
- Make one person the super-admin, and the rest co-admins
Pro's: If someone leaves, it's far easier to just revoke their credentials/privs
Con's: Lots more accounts to keep track of depending on the size of your team, particularly if you're company has a single Azure Account, with lots of different apps/projects hosted on it.
Personally, I prefer the second option as it's more secure/easier to revoke access to individuals.