To file online return, first of all the assessee needs to register at www.incometaxindiaefiling.gov.in. Once registered he can efile his return by uploading 'XML' file of his e-return. To create 'XML' file you can check software which is freely available for download at the above referred website. After e-filing ,the duly signed ITR-V(i.e. the acknowledgement) is required to be sent to CPC Banglore by Ordinary/Speed Post. But, if the file is digitally signed, it need not be sent to CPC. Please visit the above website for detailed guidelines.