Editing feature class using ArcObjects?

I recommend starting and finishing all edits within an edit operation inside of a try block, where a catch block would call AbortOperation.

Something I've always wondered about is whether it makes sense before starting an edit operation to check to see if there's already an operation underway, via IWorkspaceEdit2.IsInEditOperation.

The benefit of starting an edit session is that you can use the many different edit event listeners to control edit workflow if needed. You also have the ability to undo edits if a feature was deleted by mistake.

I think this document will provide to you a good source of knowledge: http://help.arcgis.com/en/sdk/10.0/arcobjects_net/conceptualhelp/index.html#//000100000340000000