IDoc Configuration

HI Experts,

From last two days I have been searching for IDoc configuration. I want to create IDoc through EDI for F110 Transaction. I searched on the google and community as well, the only thing I got is theory and different TCodes related to IDoc like WE30, WE31, WE02, WE05 etc.

When I gone through Tcode WE30- create IDoc type there is field i.e.,

Object name:                         

I don't know what to give their. if I select any thing by pressing F4, system says already exist.

if anybody having very good material regarding Idoc with proper explanation and example then forward it to me my mail id is,

pghonmode@gmail.com 

please help me out and give explanation, not only tcodes & theory but also fields which are required in particular tcodes.

thanx in Advance