Regarding the information for OCB-283 and EWSD:
1. For all those who are working in BSNL ALTTC ghaziabad conducts 6weeks to 8 weeks training for both. With a little bit of field experience the training will provide you confidence. Allthe manuals/handouts are provided there. if you have not attended the training contact any of your friend who hasattended the training and ask for manuals.
2. For those who are not working in BSNL the Documentation CD is the best way. Can be taken from ocb/ewsd incharge of your city. Ofcourse relation is required.
In the last GURU bina Shiksha nahi. You need a guru with you in field to become a guru. All these sources are just supporting ones.
regards to all