This is the first in the Workflow series of screencasts that will show you how to create specific workflows to automate or enhance the speed at which you can get your work done on your iOS device of choice.
Quickly emailing a group, like in a distribution list, is the first challenge I had to face when working from my iPad in my school. Emailing a distribution list is not possible in the Apple native Mail app (or any other mail app) on iOS. However, when using Workflow this can be done as quickly and easily as it is done on a Mac or PC. The one hint I will give you is that if you have a long list of recipients for a specific workflow I would create that list as text file and then copy and paste that text file into the recipients field in the email action in Workflow.
Workflow link: Email a group