Start Workflow Using EventReceiver

This is how you can invoke workflow using EventReceiver. You can use this code if you have multiple workflows added and you want certain workflow to be invoked based on your selection in list. In this example i have 2 workflows, sequential and parallel. Based on my selection in list one of this workflow will be invoke. You can read more in this thread

Event Receiver in SharePoint

Event receiver is a good way to handle necessary event that occurs in SharePoint. This includes item adding, delete, updated or more. This is a good video on how to use event receiver[youtube=http://www.youtube.com/watch?v=nD1epgK3158]