It return

I am going to file itr-1 , but i would like to know, so i have got a digital signature and how will i use it?

and how will generate xml file in excel2007 and one more thing i would like to know , when we register with efilling on that time i get an option register Digital signature signature so what does it mean should i go with this or not and also tell me how do we sign the form with digital signature ,? before ganerating xml or after that tell me briefly i m first time user?

thanks