If your students don’t have email addresses the simplest solution is to set up their accounts using one Gmail account and then add a + sign and a different number and/or letter(s) to the end of your email name for each student.

How it works is Gmails ignores anything in the first half of an email address after a plus sign so if you create each email with the format username+studentname@gmail.com all emails will be sent to the inbox of username@gmail.com

This also means that if you want to moderate comments on all student blogs they will be sent to your email address.

See Also: Comment moderation settings